tg05 Brewing Industrial Energy Efficiency

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Industrial Energy EfficiencyAccelerator - Guide to the brewingsectorThey UK produces 49 Mhl per year and emits approximately446,000tCO2/yr. Current CCA data shows that in the UK there are 14large breweries or packaging sites (over 1Mhl per annum), a further 35smaller breweries and circa 700 micro-brewers. This Sector Guidedescribes the IEEA findings for the UK brewing sector. The investigationcentred on the brewhouse, small pack packaging, kegging/casking andclean-in-place (CIP) as the key areas where significant improvementscould be made.

Executive SummaryThe Carbon Trust has worked with a range of industry sectors as part of its Industrial Energy Efficiency

Accelerator (IEEA), to identify where step-change reductions in energy use can be achieved through detailed

investigation of sector-specific production processes. The IEEA aims to support industry-wide process carbon

emissions reduction by accelerating innovation in processes, product strategy and the uptake of low carbon

technologies, substantiated by process performance data and detailed process analysis.

This Sector Guide describes the IEEA findings for the UK brewing sector. The investigation centred on the

brewhouse, small pack packaging, kegging/casking and clean-in-place (CIP) as the key areas where significant

improvements could be made, and opportunities categorised according to their degree of technical/commercial

maturity; that is, their relative ease of implementation and cost-effectiveness:

Wave 1: Energy efficiency best practice and process optimisation: On the basis of the best practice

survey carried out as part of the investigation, we estimate that a 5% carbon saving (22,000tCO2/year) could

be made across the sector, from the consistent application of all feasible best practice opportunities.

Furthermore, a large number of process optimisation opportunities were identified, relating to the kettle, small-

pack pasteurisation, keg/cask processing, and CIP. Those that were possible to quantify show that a further

9% reduction (40,000tCO2/year) in carbon emissions could be achieved by optimising and implementing

existing best practice process technologies.

Wave 2: Opportunities on the horizon: Some newer technologies have the potential to make step-change

reductions in energy use; these are commercially available but UK take-up has been low due to concerns over

quality impacts, lack of capital, and longer than acceptable payback periods. Areas of potential are: adding a

wort stripping column or direct steam injection to the kettle; kettle vapour heat recovery; using a heat pump torecover energy from refrigeration system condensers; and switching to flash pasteurisation or cold sterile


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Brewing Sector Guide 2

filtration for small-pack pasteurisation. An estimated 12% further carbon reduction (54,000tCO2/year) could be

achieved from such measures.

Wave 3: The future: A number of game-changing technologies have been identified but will require both a

time and financial commitment from the industry to bring them to technical and commercial fruition. We

estimate the key areas with potential to be UV pasteurisation for both kegs and small pack, as well as the

development of more precise techniques for monitoring and controlling CIP processes. We estimate that a

further 5% carbon saving (22,000tCO2/year) could be made across the sector from these measures.

The cumulative impact of these opportunities, illustrated in the carbon reduction road map shown in the figure

below, shows that a total sector carbon saving of 31% is achievable, equivalent to 138,000tCO2/yr on sector

baseline emissions of 446,000tCO2/yr. This is based on a sequenced scenario where all Wave 1 opportunities

are implemented first, so that the impact of the more innovative opportunities of Waves 2 and 3 is made againstan already reduced baseline carbon emissions level.

The table below summarises the main areas of opportunity categorised according to the three-wave approach

described above, along with their sector-wide carbon saving potential. Note that the measures are not necessarily

additive; for example, a wort-stripping column and direct steam injection are alternative boil-off reduction

technologies, and cannot both be applied. Furthermore, the sector saving potential is also affected by previous

improvements: for example, if best practice and the optimisation of existing processes has first been carried out,

then the incremental benefit of, say, cold sterile filtration will be against an already reduced starting position ofenergy use and carbon emissions. The road map graph above has taken these factors into account.

Wave(1/2/3)

Area Description

Sector CarbonSaving

AveragePayback(years)(tCO2) (%)

1 Best practice in energy Implement all feasible opportunities 22,300 5.0% Unknown

1 Process optimisation Reduce boil-off 11,200 2.5% Unknown

1 Process optimisation Increase high gravity dilution 11,900 2.7% Unknown

1 Process optimisation Optimise tunnel pasteurisers 14,000 3.1% Unknown

1 Process optimisation Optimising cask washing 3,100 0.7% 5.9

100%

14%

12%

5%

69%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Step change road map for UK brewery sector


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Wave(1/2/3)

Area Description

Sector CarbonSaving

AveragePayback(years)(tCO2) (%)

2 Small pack pasteurisation Flash pasteurisation with clean room 53,400 12.0% 2.5

2 Small pack pasteurisation Cold sterile filtration 68,600 15.4% 6.3

2 Pasteurisation Heat pump on refrigeration condenser 29,200 6.5% 2.7

2 Kettle Wort stripping column 21,500 4.8% 2.4

2 Kettle Wort steam injection 18,700 4.2% 3.2

2 Kegs/Casks One way containers Dependent on transport distance

3 CIP Real-time cleaning verification 4,600 1.0% Unknown

3 CIPCIPnovel technologies and lowtemperature detergents (ECA)

7,500 1.7% Unknown

3 Small pack pasteurisation UV pasteurisation for small pack 68,300 15.3% 6.5

3 Kegs/Casks UV pasteurisation for kegs 13,100 2.9% 1.9

Recommendations

We recommend that the brewing industry takes the following, tiered approach to energy and carbon efficiency

improvement:

Implement remaining best practice techniques and technologies: investigation has shown a considerable

potential for sector-wide savings by ensuring the consistent application of sustained best practice

management techniques and available technologies.

Optimise existing processes in the brewhouse, packaging and CIP : further, low cost savings can be

achieved through improvements to operating practices and production methods and by refinements to existing

process technologies.

Collaborate with equipment suppliers on technology trials and pilot projects: to assess the potential

impact of less proven technologies and techniques on product quality and to support the progression to cost-

effective equipment design.

BBPA and Carbon Trust support:should be sustained to ensure that the UK brewing sector has access tothe information, case studies, partnerships and innovation support funding that will enable it to achieve the

significant carbon emissions reduction potential identified as part of this IEEA project.


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Table of contents

Executive Summary .............................................................................................................................. 1

1 Introduction ....................................................................................................................................... 6

1.1 Sector background ............................................................................................................. 6

1.2 Process operations and energy ......................................................................................... 7

1.3 Sector carbon emissions ................................................................................................. 15

1.4 Issues and barriers relating to energy efficiency and change ......................................... 16

1.5 Focus processes .............................................................................................................. 17

1.6 Regulatory drivers ............................................................................................................ 18

1.7 Other business drivers ..................................................................................................... 20

1.8 Industry progress on energy saving ................................................................................ 20

2 Methodology for monitoring and analysis ................................................................................... 21

2.1 What metering/data gathering was done and why .......................................................... 21

2.2 The kettle ......................................................................................................................... 21

2.3 Small pack pasteurisation ................................................................................................ 21

2.4 Keg/cask processing ........................................................................................................ 22

2.5 CIP ................................................................................................................................... 22

2.6 Engagement with the sector ............................................................................................ 22

2.7 Participating host sites ..................................................................................................... 22

2.8 Data gathering ................................................................................................................. 23

2.9 Metering approach ........................................................................................................... 23

2.10 Best practice checklist .................................................................................................... 24

3 Key findings: best practice survey ............................................................................................... 25

4 Key findings and opportunities: the kettle - wort stabilisation ................................................. 274.1 Key differences between the sites investigated ............................................................... 27

4.2 Data to support analysis .................................................................................................. 28

4.3 Best practice process optimisation opportunities ............................................................ 35

4.4 Innovative wort stabilisation opportunities ....................................................................... 37

4.5 Summary of findings ........................................................................................................ 40

4.6 Barriers to implementation ............................................................................................... 40

5 Key findings and opportunities: small pack pasteurisation ...................................................... 41

5.1 Process description ......................................................................................................... 41

5.2 Data analysis and modelling ............................................................................................ 43

5.3 Process optimisation opportunities .................................................................................. 47


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5.4 Innovative opportunities and significant change .............................................................. 50



6 Key findings and opportunities: keg and cask processing ....................................................... 55

6.1 Keg processing ................................................................................................................ 55

6.2 Cask processing .............................................................................................................. 59



7 Key findings and opportunities: clean-in-place .......................................................................... 64

7.1 Data analysis ................................................................................................................... 64


7.3 Innovative opportunities ................................................................................................... 67



8 Summary of opportunities ............................................................................................................. 72

8.1 Overview .......................................................................................................................... 72

8.2 General best practice energy efficiency opportunities ..................................................... 73


8.4 Innovative opportunities ................................................................................................... 73

9 Sector roadmap and next steps for the UK brewery sector....................................................... 78

9.1 The step change roadmap ............................................................................................... 78

9.2 Elements of the roadmap ................................................................................................. 79

9.3 Next steps for the UK brewery sector .............................................................................. 81

Appendix 1: Metering rationale .......................................................................................................... 84

Appendix 2: Good practice checklist ................................................................................................ 87

Appendix 3: Kettle technologies and business cases .................................................................... 99Appendix 4: Small pack technologies and business cases .......................................................... 104

Appendix 5: Keg/cask technologies and business cases ............................................................. 112

Appendix 6: CIP technologies and business cases ...................................................................... 115


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1 Introduction

1.1 Sector background

Beer has been a staple part of British food since the early 12th century; it is a much-loved part of British culture,

and the industry supports around 400,000 jobs, as well as sustaining many other UK businesses. The British

Beer and Pub Association (BBPA) is the leading trade organisation representing the UK beer and pub sector. Its

members account for 96% of beer brewed in the UK and own more than half of Britain's 53,000 pubs.

Until the 16th century beer was brewed in the home, on farms, in wayside taverns and, later, in the great

monasteries. Its commercial mass production is estimated to have started in the early 16th century; with records

of production available from 1750. They show that UK beer production peaked in 1979 at 67.5 million hectolitres

(Mhl) but since then the production has declined gradually to its current level of less than 49 Mhl per year. These

declines are synchronous to the changes in consumption trends. There have been marked declines followingrecessions at the beginning of 1980s and 1990s, the decline in heavy industry and, more recently, following

consumer trends towards wine and other drinks.

Figure 1UK beer consumption and production (1960-2009)1

1 Source: BBPA


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Against the background of declining production, there has been a rationalisation within the industry. The earliestrecord of number of breweries is in 1690, which shows around 48,000 breweries in existence at that time. In the

past thirty years, the number of industrial breweries has reduced from 140 to 49; however the number of micro-

breweries has gone up in this period. Current CCA2 data shows that in the UK there are 14 large breweries or

packaging sites (over 1Mhl per annum), a further 35 smaller breweries, and circa 700 micro-brewers. Heineken

UK (formerly known as Scottish & Newcastle), is the market leader, with more than a quarter of UK beer sales.

The next three largest companies are also foreign-owned companies; Molson Coors UK; AB-InBev UK; and

Carlsberg UK. On the other hand, Irish-based Diageo is famous for its Guinness brand and is a major

multinational3.

There are some changing trends in beer consumption that are worth noting. Data from the BBPA CCA 2010

report shows that the volume of ale and stout, the traditional British beers, has been slowly replaced by lager,

changing the proportion of ale and stout to lager from 99:1 to 25:75 over the last 50 years. Climate Change

Agreement (CCA) data for the brewery sector shows that the majority of exclusive ale producers are relatively

small in size (annual production below 1 Mhl), whilst all the exclusive lager producers fall in the large category

(annual production greater than 1 Mhl).

There has also been a shift from drinking in pubs, clubs and bars to taking beer home for consumption. Take-

home sales now account for 47% of the total sales volume as against 10% in the 1970s. Change in the

packaging mix is consistent with the growth in take-home sales; the percentage of returnable bottles, kegs and

casks is steadily declining matched by the percentage of non-returnable bottles and cans increasing. The volume

sold in cans has doubled in the last 30 years.4

From the perspective of energy and water consumption, the UK brewing industry has seen some encouraging

trends. Even though, for lager, lower fermentation temperatures and cold-conditioning periods result in higher

requirements for refrigeration and thus electricity consumption, and specific energy consumption (SEC) in

manufacturing is higher for small-pack products, BBPA data shows that the overall SEC for the industry has

fallen by 53% since 1976. Overall water consumption has declined by 49% over the past 30 years and total

carbon emission for the industry has dropped by 55% from its 1990 level. These achievements are discussed in

detail further in this report.

1.2 Process operations and energy

1.2.1 Process overview

Brewing is the production of alcoholic beverage through fermentation. Brewing specifically refers to the process

of steeping, and extraction (chemical mixing process), usually through heat. The brewing process uses malted

barley and/or cereals, un-malted grains and/or sugar/corn syrups (adjuncts), hops, water, and yeast to produce

beer. Brewing has a very long history, and archaeological evidence suggests that this technique was used in

ancient Egypt. Descriptions of various beer recipes can be found in Sumerian writings, some of the oldest known

writing of any sort.

Most brewers in the UK use malted barley as their principal raw material. The main ingredient for the brewery

process (barley grain) goes through malting process (this process is usually done in a dedicated maltings facility

separate to the brewery).

2 Climate Change Agreements between industry trade associations and the Government allow industry members to claim an80% discount on the Climate Change Levy. In return companies must hit energy/carbon saving targets and report onprogress.

3Source: BBPA4Source: BBPA


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First the grain is steeped in water. This prompts germination which generates -amylase and -amylase amongother enzymes. These enzymes are used later to help the starch in the grain be broken down to sugar. Before

the malted grain is delivered to the brewery it is usually roasted or dried in a kiln, with longer roasting periods

resulting in a darker and stronger tasting beer.

1. The first step in brewing involves milling the malted grain to increase the surface areas available so that

a high yield of extracted substances can be obtained. This is either done wet or dry.

2. The crushed malt (grist) is then mixed with heated water in the mash tun (a large vessel). During

mashing natural enzymes within the malt break down much of the starch into sugars which play a vital

part in the fermentation process. This process usually involves the mash being heated to several

specific temperatures (break points) and resting at these temperatures where different enzymes break

down the starch into the desired mix of sugars. The sugar and starch solution that is created in theprocess is called the wort. Before the mash is fi ltered the temperature is raised to 75C to deactivate

enzymes.

3. To separate out the wort from the grist the mash is either sent through a lauter tun or mash filter.

o A lauter tun is a large vessel up to several meters wide and tall which has a slotted bottom (like a

giant sieve), which allows the wort to fall through while retaining the spent grain grist behind. To

extract any remaining available sugars fresh water is sprayed onto the mash after the initial wort

has drained through the slotted base (sparging).

o A mash filter is comprised of a series of plates where the mash is compressed to remove as much

wort as possible. The remaining mash is sparged but less water is needed as the mash filter

provides a larger cross section of mash with less depth to penetrate than in a lauter tun.

o In some cases the lauter tun is combined with the mash tun to form a mash vessel. In this case, the

wort run off is directed through a series of slotted plates at the bottom of the tun. The mash floats

on top of the wort. This tends to be the slowest wort separation system although it is the lowest cost

in terms of capital outlay.

4. The next step involves the wort being heated in a wort copper or kettle; wort stabilisation involves the

boiling and evaporation of the wort (about a 4-8% evaporation rate) over a 1 to 1.5 hour period. The boil

is a strong rolling boil and is the most energy-intensive step of the beer production process.

The boiling sterilises the wort, coagulates grain protein, stops enzyme activity, drives off volatile

compounds, causes metal ions, tannin substances and lipids to form insoluble complexes, extracts

soluble substances from hops and cultivates colour and flavour. During this stage hops, which extract

bitter resins and essential oils, can be added. Hops can be fully or partially replaced by hop extracts,which reduce boiling time and remove the need to extract hops from the boiled wort. If hops are used,

they can be removed after boiling with different filtering devices in a process called hop straining.

5. In order to remove the hot break or trub (denatured proteins that form a solid residue), the boiled wort is

clarified through sedimentation, filtration, centrifugation or whirlpool (being passed through a whirlpool

tank). Whirlpool vessels are most common in the UK.

6. After clarification, the cleared hopped wort is cooled. Heat exchangers for cooling are of two types:

single-stage (chilled water only) or multiple-stage (ambient water and glycol). Wort enters the heat

exchanger at approximately 96-99C and exits cooled to pitching temperature. Pitching temperatures

vary depending on the type of beer being produced. Pitching temperature for lagers run between 6-

15C, whilst for ales are higher at 12-25C. Certain brewers aerate the wort before cooling to drive off

undesirable volatile organic compounds. A secondary cold clarification step is used in some breweriesto settle out trub, an insoluble protein precipitate, present in the wort obtained during cooling.


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7. Once the wort is cooled, it is oxygenated and blended with yeast on its way to the fermentation vessel.During fermentation, the yeast metabolizes the fermentable sugars in the wort to produce alcohol and

carbon dioxide (CO2). The process also generates significant heat that must be dissipated in order to

avoid damaging the yeast. Fermenters are cooled by coils or cooling jackets. In a closed fermenter,

CO2 can be recovered and later reused. Fermentation time will vary from a few days for ales to closer

to 10 days for lagers. The rate is dependent on the yeast strain, fermentation parameters and the taste

profile that the brewer is targeting.

8. At the conclusion of the fermentation process the beer is cooled to stop the action of the yeast, then the

yeast is removed through settling or through a centrifuge (although with real ale: some yeast is retained

and after the ageing it is added with the beer into the barrel).

9. Beer aging, conditioning or maturation is the final production step. The beer is cooled and stored in

order to settle remaining yeast and other precipitates and to allow the beer to mature and stabilize.Different brewers age their beer at different temperatures, partially dependent on the desired taste

profile. Beer is held at conditioning temperature (-1C to 10C) for several days to over a month, and

then chill-proofed and filtered (the process for real ale is different to lager as the yeast is not filtered out

of the beer).

10. With the beer at a temperature of -1C, a kieselguhr (diatomaceous earth or mud) filter is typically used

to remove any precipitated protein and prevent the beer from clouding when served at a cool

temperature. With real ale the beer is not filtered so that the yeast is still live when it goes out in the

cask.

11. In high gravity brewing (high alcohol content), specially treated de-aerated water is added after the

filtration stage to achieve the desired final gravity. The beers CO2 content can also be trimmed with

CO2 that was collected during fermentation or from external supplies if enough CO2 is not recoveredon site.

12. After being blended the beer is then sent to the bright (i.e. filtered) beer tanks before packaging.

13. Beer that is destined for bottles or cans is sent to the fillers where a vacuum or counter pressure filler

will be used to fill the bottles or cans. Other beer will go to the flash pasteuriser and be filled at a later

stage in, casks, kegs or sometimes directly into tankers (for real ale the beer is not pasteurised as this

would kill the yeast).

14. The beer must be cleaned of spoiling bacteria to lengthen its shelf life. One method to achieve this,

especially for beer that is expected to have a long shelf life, is pasteurisation, where the beer is heated

to 75C to destroy biological contaminants (this is not carried out with real ale as the process would kill

the yeast in the beer). Different pasteurisation techniques are tunnel or flash pasteurisation:

o Flash pasteurisation involves the beer being heated for a short amount of time and then being

bought down in temperature in a heat exchanger prior to filling.

o In-pack pasteurisation is the pasteurisation of beer that has already been packed in bottles or cans,

by bringing the whole packed beer container up to temperature by heating with hot water. This is

typically done in a tunnel pasteuriser.

15. Finally, the packaged beer undergoes any secondary or retail packing processes and is ready to be

shipped.

The diagram below shows these 15 process steps, with annotation as to where cold liquor (cold water), hot

liquor (hot water) and de-aerated water are added and where heating and cooling take place.


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Figure 2Brewing process diagram


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1.2.2 Process energy use

Energy consumption in any typical brewery is divided into two parts: electrical energy consumption and thermal

energy consumption. Thermal energy or heat is typically generated using different fuels in a boiler house. Coal

and oil were the traditional boiler fuels but the majority of boilers in the UK now run on natural gas, with fuel oil

used as a backup. Process heating typically accounts for a large share of thermal energy. Electrical energy is

either sourced from grid or generated on-site, for example, in a combined heat and power (CHP) system.

Refrigeration for process cooling typically accounts for a significant amount of electricity. An estimated CO2

emission breakdown by main process areas in percent of total energy consumption is shown in Figure 3 for a

typical brewery.

Figure 3Brewery CO2 consumption breakdown from a typical 2Mhl brewery5

Brewhouse

38%

Packaging

35%

Cold Block

11%

Waste Water

7%

Building services

5%

Warehouse

4%

Typical site CO2 breakdown

From this information the main energy users can be identified as the brewhouse, packaging and the coldblock. By looking at data gathered during previous studies at several large breweries (2+ Mhl/year) we have

been able to build an approximate model of where both electrical and thermal energy is consumed in these

individual sections of the brewery.

The following diagrams and charts demonstrate what type of inputs each process requires and how much energy

each stage consumes. In each stage the areas that we have focused on may not be broken down into exactly the

same stages that the process diagram indicates. This is down to insufficient metering for each process.

5Source: Camco data and IEEA data collection


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As the charts below indicate, the vast majority of thermal energy is used in brewing operations andpasteurisation, while electricity consumption is more evenly divided among fermentation, beer conditioning and

utilities.

Brew House

Figure 4: Brew house process diagram

Brew House

2. Mash Tun 5. Whirlpool4. Kettle3. Lauter Tun

or Mash Filter

6. Wort Cooler

Vapour heat

recovery

1. Milling

Steam

Cold Liquor

Hot Liquor

Deaerated Liquor

Cooling

Electricity

Heat lost

through hot

spent grain

InFigure 5 below, the wort cooler has been combined with the whirlpool and kettle as a single energy user. The

wort cooler also recovers a lot of heat as hot liquor (water) which is subsequently used to mash in the next batch,

therefore the virgin energy consumed for mashing is not as much as might be imagined as the energy recovered

by the wort cooler reduces the energy input required for mashing in.

Figure 5Brewhouse energy demands

The largest energy consumer in this area is clearly the kettle and any energy improvements in this area could

have a significant impact to overall brewery SEC (Specific Energy Consumption measured in this report askWh/hl).


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Cold Block

Figure 6: Cold block process diagram

In Figure 7 below, the centrifuge has been combined with the fermenters, and the beer cooler has beencombined with the filtration process.

Figure 7Cold block energy demands

From the data available the electrical energy used in fermentation and filtration are the highest users in this area

and involve multiple processes (maturation involves cooling tanks only). The thermal inputs to filtration and

fermentation are down to the local clean-in-place (CIP) systems. The filters use a considerable amount of hot

caustic solution to regenerate.


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1.3 Sector carbon emissions

1.3.1 Carbon dioxide emissions

In the UK in 2009, 43 Mhl of beer was produced, and 49 Mhl of beer was packed, by the 49 sites covered by the

sectors CCA(ie, 6 Mhl was imported in bulk but packaged in the UK). From these sites a total of 446,000 tonnes

of energy-related carbon dioxide (tCO2) was created, either through electricity or direct fuel consumption on site.

From CCA data this gives average specific energy consumption (delivered) of 37.5 kWh/hl and emissions of 10.4

kgCO2/hl

1.3.2 Brewery archetypes

We plotted a scatter graph of the 49 sites included in the BBPA CCA of production versus specific delivered

energy per hectolitre of beer produced, and specific CO2/hl of beer produced. This allowed us to draw a line of

best fit or performance curve through where the sites lay on the graph. By combining this line with a production

dividing line (1 Mhl/year production was close to the average and also a sensible division between smaller and

larger sites); the graph is divided up into four sections, or archetypes:

Large sites with higher Specific CO2 (kgCO2/hl product)

Large sites with lower Specific CO2

Small sites with higher Specific CO2

Small sites with lower Specific CO2

Figure 9CCA brewery archetypes: total CO2 ratio vs. total production with 90% of sites falling between the greylines


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Table 2CCA brewery archetypes

Numberof sites

Production(hl)

UKproduction

(%)

Carbonemissions

(tCO2e)

UK-wideemissions

(%)

Large sites - Higher specific energy 7 23,249,238 48% 229,170 51%

Large sites - Lower specific energy 7 16,890,668 35% 106,892 24%

Small sites - Higher specific energy 15 4,705,475 10% 76,901 17%

Small sites - Lower specific energy 20 3,362,530 7% 32,680 7%

We can draw the following conclusions from this analysis: The 14 largest sites account for 83% of the volume of beer packaged and 75% of the total sector carbon

emissions;

Small sites with a high SEC are the next most significant group accounting for 10% of volume and 17% of

sector carbon emissions;

In general, larger sites have a lower SEC; and

Implementing emissions reduction projects in larger sites has the greatest potential to reduce sector

emissions.

1.4 Issues and barriers relating to energy efficiency and change

1.4.1 Authority for change within the UK brewery sector

Of the 49 brewery sites in the UK under the sectors CCA, 14 account for 83% of all beer produced and 7 5% of

sector emissions. These 14 large breweries are solely lager or mixed breweries and replicability of opportunities

within these sites will lead to the highest source of emissions reductions within the sector.

However, a large amount of beer is brewed under license in the UK, with many of these sites owned by

multinational companies based outside the UK, producing the same brand in many locations around the world, as

well as similar beers under different brand names, depending on location and market. Hence, the need to seek

agreement from internationally based head offices for changes of UK based plants creates a significant barrier to

change.

A potential barrier to energy and carbon emission saving opportunities that may affect the recipe of beers or

fundamental packaging methodologies (e.g. reductions in kettle boil-off or different pasteurisation techniques)could understandably be the manufacturing standards used by non-UK companies that apply to multiple

breweries around the world.

If significant energy saving opportunities can be identified without any negative impact on beer quality or taste,

then the key to enabling these opportunities for the UK industry may be the effective engagement of such

international stakeholders. These companies are all committed to reducing their environmental impact across

each market they operate in.

1.4.2 Heritage and tradition

Many UK brewers rely on brands that claim to have been brewed in the same way for long periods of time. This

builds a brand that the consumer can associate with and trust to deliver quality with a recognisable taste.

Encouraging any changes to the brewing process to save energy could be met with opposition if these changesmight impact on marketability, and any such changes would need to be measured in terms of the impact on


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quality and taste. The customer is king and many breweries perceive that their customers have great loyalty totheir beer being produced in the traditional way in the traditional place.

This should not deter this project from investigating opportunities that could lead to large emissions reductions,

but it demonstrates that the Carbon Trust and its partners must engage sensitively with brewing companies to

examine how to mitigate any issues that may arise in this area.

1.4.3 Awareness of best practice

Initial site visits have shown that, on the whole, sites are aware of what is termed best practice for energy

efficiency. However, this does not mean that all best practice opportunities have been carried out where possible.

Where best practice has not been carried out, it is usually down to lack of available capital, resources or

expertise or the barriers discussed above.

By sending out a best practice survey to the whole sector we aimed to understand the level of remaining bestpractice implementation potential, including the key opportunities still outstanding for the sector and the main

reasons they have not already been implemented (see Section 3 for the summary of the best practice survey

results).

1.4.4 Sector inclusion

The UK brewery sector is made up of three main types of site: large lager and mixed breweries; small ale-only

breweries; and micro-breweries that do not participate in the CCA. The way in which each type of brewery makes

beer is similar, but the technology used can be very different.

While looking for opportunities for this project care has been taken to include areas of focus that have an effect

on all parties involved. This has been carried out to reduce the likelihood of disenfranchisement and maximise

the potential benefits of having the whole sector involved.

1.5 Focus processes

Through choosing the following processes to focus on we aimed to direct the project into the investigation of the

highest energy using processes with the potential for improvement, as discussed and agreed in initial sector

stakeholder meetings.

Kettle. As shown in Figures 3 and 5, the kettle is the biggest energy user on site, so we have looked into

how much energy is required to boil several different types of beer. By looking at multiple breweries we have

been able to see what effect different kettle technologies have on the energy demand of the brewery process

and have used this information for building business cases for alternative approaches.

Small pack pasteurisation. The second biggest area of energy use in the brewery is in packaging. Within

this area the pasteurisation of the beer is the largest user of heat and a considerable user of water and

electricity. We have monitored two distinctive types of small pack pasteurisation:

o Flash, where the beer is heated up to pasteurisation temperature and then brought back down in a

plate pack heat exchanger and then bottled; and

o Tunnel, where the beer is bottled or canned and then raised in temperature by spraying hot water

over the containers to bring the whole package up to pasteurisation temperature.

Currently, the use of flash pasteurisation is relatively rare in the UK due to a number of perceived product

quality issues. By looking at these two types of pasteurisation we have been able to build a case study of

the two systems, showing the cost involved with each and the implications for moving from one technology to

the other. This has also been used to quantify savings from using alternative pasteurisation techniques such

as ultra-violet light.


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Kegging and casking. The third area that we have focused on is in kegging and casking. After our initialsite visits we identified that the way in which kegs are cleaned was different at each site and there was no

common approach. The monitoring programme aimed to understand what the different heat loads within the

keg cleaning process are and recorded exactly how much water, electricity and compressed air is used to

process each keg at different sites. By calculating these utilities benchmarks we assessed the potential

savings from alternative technologies in both the keg cleaning and flash pasteurisation for kegging.

Cask cleaning has been largely been ignored over recent years as the ale industry has been in decline

against lager. Resurgence in ale from the cask means that this area needed to be revisited and so we have

tried to understand how much energy is used in cleaning a cask and to define standards for current best

practice.

Technical difficulties acquiring data from kegging plants during the analysis period resulted in the data being

limited to electrical, heating and water demands for two of the sites monitored. The compressed air recorded

was not reliable and so has not been included in the analysis.

The implication of the decline in casking means that we were unable to find no real innovative technologies

in the market place.

Clean in Place (CIP)within breweries is a significant energy and water consumer. Camco carried out an

extensive analysis of CIP as part of the Dairy Sector IEEA project. It is believed that much of this information

and knowledge is transferable to the brewing sector, therefore metering of CIP was not carried out under the

scope of this project. Where data already exists we have sought to establish benchmarks of key parameters

for comparison.

1.6 Regulatory drivers

Climate Change Agreement

The UK brewery sector is covered by a Climate Change Agreement, under which its members receive an 80%

(65% from April 2011) discount on the Climate Change Levy, which is a surcharge on energy bills. The CCA

requires companies to reduce their carbon emissions according to an agreed series of milestone targets or risk

losing the discount. The scheme provides an incentive to improve energy efficiency: if the milestone reduction

target is not achieved, the CCL discount is lost on all el igible energy and fuels purchased. As a consequence, the

brewery sector has performed well, reducing energy consumption by 16% since the start of the scheme in 2001.6

The brewing sector has met its final targets, resulting in the discount being received up to March 2013. The

Government has recently announced that Climate Change Agreements will continue until 2023, albeit with a

reduction in the discount from 80% to 65% up to April 2013.

EU Emissions Trading Scheme

The EU ETS is an emissions reduction framework based on the cap-and-trade principle. First implemented in

2005 across the EU, it covers selected energy intensive industries such as cement and steel production, as well

as all combustion plant above a certain size threshold (20MW). If a site meets one of these criteria then it must

join the EU ETS, even if it is also covered by a CCA. Sites in the EU ETS are assigned an emissions cap and

they must buy emissions permits to hit the cap if they are not able to reduce their emissions internally. Large

brewery processing sites are covered by the EU ETS on the basis of their boiler plant, which typically will be

above the size threshold.

Phase 3 of the EU ETS runs from 2013 to 2020.

6Source: BBPA


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F-Gas Regulations

HFC refrigerants are affected by EU Regulation 842/2006 which covers certain fluorinated greenhouse gases (F-

Gases) commonly used in refrigeration equipment. HFCs are potent greenhouse gases, with global warming

potential of around 2,000 times that of CO2. In the past, refrigeration and air-conditioning systems have leaked

potent HFCs into the environment. Some brewery sites use separate refrigeration plants with HFCs for areas

such as cold storage.

The F-Gas regulations require operators of air-conditioning and refrigeration plant to prevent refrigerant leakage

and carry out regular leak tests; recover HFC refrigerants during maintenance and plant decommissioning;

maintain accurate records and ensure that equipment is appropriately labelled and operated and maintained by

suitably trained personnel.

Ozone depleting substance regulations (R22 phase out)

The phase out of HCFCs for maintenance of existing refrigeration and air-conditioning systems began at the end

of 2009, as required by EU Regulation 2037/2000 on ozone-depleting substances. The regulation banned the

use of virgin HCFCs for maintenance from the end of 2009 and recycled fluid from the end of 2014. This is of

crucial importance for many companies and means that all users of R22 and other HCFC systems, if they have

not already, need to consider alternative refrigerants or the purchase of new equipment. Other clauses in the

regulation also affect the use of existing HCFC systems.

It is important that R22 users have plans in place for the phase out of HCFCs as it is not recommended to rely on

the 2014 recycled fluid phase-out date, as this date could be brought forward as part of the review process. The

amount of fluid being recycled has in fact turned out to be very small to date, so there is no guarantee that

sufficient supplies of recycled R22 will be available between 2011 and 2014.

An alternative in some refrigeration plant is to use drop in replacement gases, but in nearly all cases these have

a degrading effect on refrigeration plant energy efficiency.

IPPC

Integrated Pollution Prevention and Control (IPPC) has been in place since 2005 and is a regulatory system that

employs an integrated approach to control the environmental impacts of certain industrial activities. It involves

determining the appropriate controls for industry to protect the environment through a single permitting process.

This UK Guidance for delivering the PPC (IPPC) Regulations in this sector is based on the Best Available

Techniques (BAT) reference document BREF produced by the European Commission7. For the brewery industry

the relevant reference document is (BREF 08.2006) Food, Drink and Milk Industries. The key environmentalissues managed by the permitting system are:

Energy use

Water use

Effluent management

Waste handling

Accident risk

7Further information on the European IPPC Bureau and the BREF document may be found at http://eippcb.jrc.es/reference/


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Hygiene

The system covers operators who are treating and processing vegetable raw materials which are intended for the

production of food products with a finished product production capacity greater than 300 tonnes per day. To gain

a permit, operators have to demonstrate that the techniques they are using, or are proposing to use, are on the

BAT list.

1.7 Other business drivers

Brewery processing is energy and water intensive and the introduction of carbon-related costs as well as rising

utility prices means there is ongoing pressure to reduce utili ty usage. This is compounded by the squeeze on

product sales prices applied by the major customerssupermarketswho are in a position to dominate the

supply chain and who often require their suppliers to take the pain of product discounts and promotions in the

stores. Cost minimisation is a powerful driver.

Another driver is corporate responsibility where, in addition to meeting any regulatory requirements, a brewery

company wishes to demonstrate to investors, environmental organisations, the local community and the wider

public its commitment to being proactive on climate change: for example, by setting voluntary carbon reduction

targets; producing product carbon footprints; or investing in environmental initiatives which reduce energy use

and carbon emissions.

1.8 Industry progress on energy saving

Beer brewing and processing into consumable products is complex and energy intensive. The internal and

external pressures on the industry to reduce costs have led to the brewery sector being progressive in terms of

energy efficiency. This in turn means that good practice in energy management is already quite widespread

(although there is still potential for improvement, as described in Section 3), and that many of the cost-effective

technology opportunities for reducing energy consumptionsuch as improved controls, or more efficient motors

and drives - have already been implemented at some sites. The good practice survey (Section 3) shows that

there are still significant opportunities available, and perhaps the best way to address this is to raise awareness

of what is possible at a site level.


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2 Methodology for monitoring andanalysis

2.1 What metering/data gathering was done and why

The monitoring design and associated data gathering carried out as part of this project concentrated on the first

three of the four focus areas described in Section 1.5. The objective of the monitoring exercise was to deploy

additional meters to supplement the information that could be collected from the existing sites SCADA systems

to build up a more detailed understanding of the following process energy consumptions:

The kettle/wort copper

Small pack pasteurisation

Keg/cask processing

Virtually all breweries in the UK have these processes as part of their facilities, meaning the opportunities

identified in these areas will have the widest possible potential for replication across the UK brewing industry (for

further details, see the metering rationale in Appendix 1).

2.2 The kettle

For the kettle we wanted to understand how much energy is used to process the wort. For each type of beer, a

target % boil-off or evaporation is predetermined and then the wort is heated for a time period to produce this

reduction. We measured the energy going into the kettle and the level of wort in the kettle during the boiling

process to determine how efficiently this energy was used to achieve the required evaporation.

With data from three different wort heating systems (three different breweries), we were able to approximate the

potential savings to be made through using alternative technologies. That is, by understanding the relationships

between boil-off and energy consumption for different kettle types, we were able to quantify the benefits from

technologies that claim to reduce evaporation energy requirements.

2.3 Small pack pasteurisation

The heat energy used in small pack pasteurisation is used to raise the temperature of the beer up to a set level

so that pasteurisation can occur. We measured the heating energy, electrical energy for pumping and water

consumed over a period of time then divided it by the bottle count on a bi-daily basis to get a specific metric for

tunnel pasteurising systems.

We did not meter a canning line as there were more systems running bottle pasteurisers in the sites that wevisited than canning lines, so bottle pasteurisers were targeted.


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2.4 Keg/cask processing

To look at how energy savings could be made with kegs and casks we first needed to know how much energy is

used in keg and cask processing. For casks, the process varies from site to site and so we compiled a list of five

different sites showing how much heat, water and - where possible - electrical energy and compressed air is used

to process each cask. From this list we were able to identify the key differences and best practices available, to

determine the savings that could theoretically be made if all cask sites moved to that option.

This process was also carried out for kegs. Both of these figures were then used to work out the emissions

savings associated with alternative packaging technologies.

2.5 CIP

CIP was not specifically metered during the monitoring process since much CIP monitoring had been done underthe IEEA dairy sector project. However one ale production site did have comprehensive data available for heat

and water input to CIP. Lessons from the dairy sector IEEA project were applied to existing CIP data provided by

the brewing sector project partners. In the dairy sector IEEA project, the heat input for CIP detergent tanks in

several systems was measured over a two week period at two dairies. This heat input was then divided by

production over this period to give a specific heat consumption figure based on production. Although this figure

was obtained for a different industry, dairy processing plants and breweries share common CIP problems, both

sending fluids through multiple tanks and processes which have to be cleaned to a high level.

Although the cleaning requirements for milk and beer are different owing to the differing viscosities and chemical

properties the nature of CIP systems and their operational parameters are similar in both industries in that both

run caustic and acid cleaning solutions, at similar temperatures to lines and vessels. The notable difference for

the brewing industry is that a lot of hot water product pushes and line flushes are used between batches and

optimisation represents a significant area for water and subsequently heat savings.

This dairy analysis will be used in conjunction with available brewery energy data to gain an understanding on

CIP costs and produce some indicative figures for energy saving opportunities. Relevant technologies have been

analysed and potential energy savings and project costings have been carried out where the available data

permits.

2.6 Engagement with the sector

During the study there was continual engagement with the sector laying out the progress with the investigations

and the direction that we were intending to follow. This was initially done through agreement with the five

companies providing sites for metering, agreeing which site would be the most suitable, and then through regular

update emails, project steering group meetings and a final workshop, in which a wider industry group (including

technology companies, equipment suppliers and academics) participated in a discussion on the benefits and

barriers relating to the opportunities identified.

2.7 Participating host sites

Five companies volunteered five sites as hosts for the IEEA Stage 1 project investigation. Out of these sites there

are three large sites with lower SEC, one large site with higher SEC and one small site with higher SEC. This

group is therefore representative of archetypes that represent 93% of sector volume and carbon emissions.


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When choosing the most suitable sites to work with there were a number of considerations to take into account.By working with larger sites the opportunities highlighted can be rolled out over the largest proportion of the

market (in terms of beer production volume and emissions). But working with smaller sites can often prove fruitful

as small organisations are often much more free to implement and trial new technologies than larger companies.

Selecting two sites with similar production volumes, but different SECs allowed us to compare directly the effects

that different innovative technologies may have on energy consumption at higher and lower energy intensity

sites.

From these five sites, three were selected for additional metering in order to give a clearer picture of the energy

consumption in the focus areas and the potential for savings through the adoption of new and innovative

technologies. The information already available from the site SCADA systems for the other two sites was deemed

adequate, allowing the data gathering budget to be used in the most efficient manner.

2.8 Data gathering

Data on process energy performance was gathered in the following ways:

Historical CCA data from UK breweries;

Meetings with site engineers over the course of the metering programme;

Data collected during the metering programme itself; and

An energy good practice check list that was sent out to industry members.

2.9 Metering approach

Having focused the metering strategy on the kettle, small pack pasteurisation, keg and cask processing, amonitoring plan was devised to collect process performance data whilst minimising disruption to the day-to-day

running of the site. The approach involved looking at the individual processes that needed to be understood in

more detail, highlighting the data needed to build this picture.

The first step was to assess the range of information already being recorded on the sites SCADA systems, to

identify data gaps and to specify the data collection hardware to be installed in order to build up a complete set of

data. The appropriate metering technology was then specified and installed by the Carbon Trusts IEEA meter

data services contractor and either connected to the sites SCADA system or operated independently of site

systems, with the data from both sources combined for analysis after the end of the monitoring period.

Ease of metering

Collecting identical data sets from the target sites was not possible, as the data that could be extracted from the

SCADA systems, or the variables to be metered, varied from site to site, depending on the age and installation ofthe systems. Older SCADA systems have limited memory and so the number of variables that were monitored in

such cases was limited, reducing the amount of data that could be combined with any additional metering for

analysis.

Typical metering devices installed at the three sites: Steam meters

Cold and hot water flow meters

Compressed air flow meters

Temperature sensors

Pressure sensors

Level sensors

Electricity meters


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Data Integrity

The metering devices were installed between December 2010 to February 2011 and data collection from new

metering came online in a phased manner from early February through to early March. The target minimum data

collection duration was a two-week period, since brewery operations normally run 24/7 with little variation and a

representative data set should be achieved over that period.

Through data collected from all of these sources process energy models were compiled that enabled the review

of energy consumption during the monitoring period and the identification of any irregularities during process

runs.

It should be noted, that at the time of writing, not all data had been analysed due to various operational delays

relating to meter installation, therefore the breadth and depth of the data set, whilst representative, is not as

comprehensive as originally planned. Where any assumptions have had to be made as a result of this we have

indicated them clearly.

2.10 Best practice checklist

During the project a survey of energy best practice in energy efficiency was sent to industry members. The aim of

this survey was to gain an understanding of how widespread the take-up of good practice was across the

industry, and also to raise awareness of energy related issues and the IEEA programme itself. The survey

comprised a checklist of around 150 questions, divided into the following sections:

Compressed air

Building and lighting

Cooling and refrigeration

Boilers and steam distribution

Vacuum

Waste water treatment

Process energy

Energy management practices

Whilst best practice is not directly in the scope of the IEEA project this exercise allows companies to benchmark

themselves against the industry and drive forward best practice, and allows us to highlight potential areas for

improvement later in this report.

The results of the IEEA investigations are shown in the following sections:

Section 3: summary results from the best practice survey

Section 4: key findings for the kettle process

Section 5: key findings for small pack pasteurisation

Section 6: key findings for keg and cask processing

Section 7: key findings for clean-in-place

Whilst Section 8provides a summary of innovative energy saving opportunities relating to these process areas

and Section 9some recommendations on next steps for the sector.


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3 Key findings: best practice survey

The pie chart below illustrates how, for the 10 companies that responded to the survey, a quarter of the

measures classed as best practice have not yet been carried out, but could still be implemented. There could be

good remaining potential for energy savings within the industry simply based on the implementation of further

low, or no-cost measures. Whilst this is not the focus of the IEEA programme, energy managers within the

industry should make sure that they have not overlooked any of these measures that may apply to their sites.

The full analysis of survey responses from the 10 different sites (all separate companies) is shown in Appendix 2,

which also provides the full list of best practice measures.

Figure 10Summary of responses from the best practice survey

Some examples of the reasons that were chosen for not possible responses were:

Payback deemed too long

Not relevant to our specific processes / operation

Impact on production downtime

Lack of people skills

Lack of available capital budget


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Process change control restricted to group level

From the collated responses there were several opportunities that half or more of the respondents thought were

possible, and were either easy to implement or could lead to substantial savings. These opportunities included,

for example:

Installing a flue gas economiser to use the waste heat from the boiler flue gas for preheating the boiler feed

water saving between 46 % on annual fuel bills

Improving boiler burner efficiency through oxygen trim with flue gas analysis (2-3% fuel savings for out of

spec burners)

Install VSDs on air compressors

Whilst the survey provides a useful indication, the true value of such opportunities will only be assessable on a

site-by-site basis, through more detailed analysis of the relevant process area.


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4 Key findings and opportunities:the kettle - wort stabilisation

Stabilising wort through boiling in the kettle has been a largely unchanged process for the last few hundred years

in the brewing industry. Only recently has this process been challenged and the real underlying process

requirements identified which affect the flavour and quality of the wort.

In summary, the main aims of the boiling process are:

Isomerisation of hops (unless using pre-isomerised hops)

Sterilisation of the wort

Removal of volatile compounds

Boiling sterilises the wort to stop spoilage during fermentation, breaks down the hops, and the gas bubbles

formed during boiling help strip the wort of unwanted volatile compounds. This process is very energy intensive

due to the large amount of heat going into the system to evaporate the wort to the prescribed level (boil-off).

4.1 Key differences between the sites investigated

Percentage boil-off

The breweries that we visited for this project had boil-offs of around 3.5% to 7.5%. In one of the breweries visited

there was one beer with a boil-off of 10% - 12%, but since this was a unique brewing process not representative

of the UK brewing industry, it has not been included for analysis in this project.

Gravity

The gravity at which the beer was brewed varied from no final dilution to up to 49% final gravity dilution. Brewing

at higher gravity, and blending after the kettle or fermentation stage, reduces the amount of wort that needs to be

boiled and hence energy consumption. When beer is brewed with a 49% end dilution only 51% of the final

packaged beer needs to pass through the kettle, roughly halving the required energy necessary.

Vapour heat recovery

Vapour heat recovery for the kettle was found on one of the host sites. The technology involves passing the

vapour from the kettle boil-off and condensing it through a vapour condenser where the heat is extracted to a hot

water tank storage tank. This hot water is then used for a pre-heater to increase the temperature of wort entering

the kettle. This technology typically works well with high percentage boil-off sites, since there is more vapour

produced and hence more energy to capture. Therefore the lower the boil-off the lower the financial return on

investment for such a system and it is not typically viable for boil-offs below 4%.


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For the IEEA site where there was vapour heat recovery, the size of the system was actually quite small and wasprimarily designed to remove odour from the vapour that drifted to the local town rather than to recover a

significant amount of energy.

Internal / external calandria

Wort heating is carried out through passing the wort through a heat exchanger known as a calandria. The

calandria can either be placed externally, outside the kettle, or placed in the centre of the kettle. The advantage

of an external type is that it can be easily inspected for maintenance but there is an efficiency advantage for the

internal variety as all of the heat exchanger is emerged in the wort, reducing heat losses as well as reducing

pumping needs.

Heat source steam or high pressure hot water

The calandrias (kettle heat exchangers) at the IEEA sites monitored were supplied with steam or high pressure

hot water (HPHW, 140C). Steam systems are more common and typically easier to maintain than HPHW

systems, but there are no flash steam losses from trapping and condensate recovery in a HPHW system, which

theoretically makes them more energy efficient. Flash losses are explained in the pasteurisation section of this

report (Section 5).

4.2 Data analysis

The diagram below shows a simplified wort kettle and shows the four variables that were recorded to support the

analysis of the specific energy used on each brew:

Wort input temperature

Temperature of wort in the kettle

Fill level

Heat input

Figure 11Simplified kettle diagram

Heat in,

temp

Fill level

Temp

of

wort

The variables have been plotted for a single boil inFigure 12 below to demonstrate a boil profile. This particular

kettle uses a dynamic boiling system where the wort is heated under pressure and then the kettle depressurised

causing vigorous boiling and flashing. At first, a consistent heat input can be seen which raises the wort

temperature to boiling point. When the temperature gets to around 100C a number of sequential heat inputs can

be seen through the evaporation phase, where the level of the wort starts to reduce until 3.5% of the wort has

been evaporated. A traditional kettle shows a similar profile, but with a more consistent heat input.


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The total energy input over the duration of the boil has been used to work out the specific energy per hectolitre ofbeer processed.

Figure 12Kettle level, temperature of the wort in the kettle and heat input for a brew at Site 1

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Kettletemperature(blueinDegC)and

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Kettle level, kettle temperature and heat input over one brew for a standard

product at one brewery

Heat input into kettle (kW) Temperature of wort in kettle (C) Level of kettle (hl)

4.2.1. Kettle energy balance

Based on a mixture of monitored and calculated data, we have derived a loss bridge for the kettle heat input. The

following diagrams shows loss bridges (energy balances) for the boiling process at two of the monitored

breweries. Delays in metering installation resulted in monitored data for the third site not being available in t ime

for this report.

Figure 13 below shows that is a 4% unaccounted for loss in the kettle, with the remaining energy being roughly

split 50:50 between heating up the wort to boiling point, and evaporating the necessary amount to achieve therequired boil-off level. Figure 14 shows a 3.5% under-measurement which is most likely due to the steam meters

not reading true.

Overall however there is a good correlation between the calculated and empirical data, suggesting that it is

credible for us to estimate the specific energy for other sites based on calculation from their boil -off percentage

and other kettle parameters.


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Figure 13Loss Bridge for the kettle process in Site 1

Figure 14Loss Bridge for the kettle process in Site 3


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The other important fact when looking at the energy used per specific volume of packed beer is the high gravity(HG) dilution rate. This is the percentage of fresh water that is added after the wort has been boiled in the kettle.

This can be before fermentation or prior to filling.

All of the beer brewed in the IEEA host sites visited boiled-off some fraction of their wort in the kettle; however,

the energy per hl needed to raise the wort temperature to boiling point will be similar across these sites. The

differentiating variables are the amount of wort that is boiled-off and the end dilution rate. A beer with 50% HG

dilution rate will only need half the heat energy per packed volume to a beer with a 0% HG dilution rate.Figure 15

shows the boil-off and HG dilution of the main products at three of the IEEA host sites monitored. Both of these

parameters have an effect on the overall specific energy consumption for packaged beer, as shown in Figure 16.

Figure 15Specific heat breakdown of the kettle at three breweries

0.0%

1.0%

2.0%

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Site 1 Site 2 Site 3

HG dilution rate (%)

Recorded boil off (%)

Figure 16 shows that the higher the brewed gravity (the HG dilution rate) and the lower the boil-off, the lower the

specific energy per unit of packed product. The losses associated with the kettle have been shown to have up to

a minimal effect on the specific energy consumption (4% maximum, shown inFigure 13)and so the important

factors remain boil-off and HG dilution. How both of these factors affect the specific energy is discussed in

Section0 below.

Boil-offr

ate


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Figure 16Specific heat from boiling in packaged beer

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atinthekettleforpackaged

beer

(kwh/hl)

4.2.2 Specific heat energy per boil

To calculate the energy needed for a boil we take the input temperature into the kettle and calculate the energy

needed to bring the wort to boil. For the theoretical boil-off for that product we can calculate the energy needed to

evaporate the liquid from the wort. These two figures were then compared to the energy actually used in the plant

as steam or high temperature hot water.

The results shown inFigure 17 show that the amount of energy used for boiling the wort of the main product at a

modern brewery is approximately 5.3 kWh/hl (average for the main product at one site over a month). The

variance demonstrated for one product is explained below in Section 4.2.3.

Figur e 17:Specific energy recorded for wort heating of one product at one site over a month

The range for other products over the same period was from 4kWh/hl to 8kWh/h with the majority of the brews

having specific energy consumptions between 5 and 6kWh/hl. The high gravity dilution rate at which the beer

shown in Figure 17 was brewed was 49%, so the overall specific energy for the wort stabilisation process,

5.3kWh/hl


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allowing for dilution, is around 2.6kWh/hl of packaged product. This is for a brewery that has an average boil-offin the kettle of 3.6%.

The more energy intensive breweries that we visited for this project had boil-offs of around 7% with a high gravity

dilution rate of 10% and so the specific energy per hectolitre of packaged product relating to wort

stabilisation/dilution would be higher at 7.8kWh/hl.

This demonstrates the energy saving potential of high gravity brewing, where this is allowed by site conditions

and the product requirements.

4.2.3 Energy variance between boils

The key variables we expect to lead to energy input variances between boils are laid out below. For each case

we have compared two of the breweries where in-depth data was available to show our rationale for quantifying

the difference in how the kettles are controlled:

Wort input temperaturewas measured to be consistent at the two breweries analysed. Both consistently

show a variation in kettle entry temperature of only 2C (between 75C and 77C). This was consistent

across a broad range of products.

Figure 18: Wort entry temperature per brew for multiple products at one brewery

The volume of the batchthe two monitored sites showed variable kettle volumes, usually due to the kettle

being topped up with fresh process water to correct any wort strength inconsistencies.

Figure 19: Maximum fill level for the kettle per brewfor one product over a month for two sites

0

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Heat losses from the systemshould remain consistent for the same kettle, boiling the same product over

a month.

The effectiveness of the heat exchange varying degrees of heat exchanger cleanliness will have an

impact on energy transferred into the wort

Specific energy input to the wortthe variance of which is shown inFigure 20 andFigure 21 below

Taking into account the above factors we plotted specific energy data for a single product type at both breweries

over a month-long period to see if there was a significant variance in heat input for the entire wort heating and

evaporation process. The first site used a dynamic pressure boiling system, internal calandria and a time-based

boil. The second site used a calorific-controlled boil (that is, only the amount of heat input necessary to achieve

the required boil-off level was input to the kettle).

As can be seen fromFigure 20 there is a significant variation in specific energy for evaporation input per brew of+/-50% from the average specific heat energy. As evaporation accounts for approximately half of the energygoing into the kettle (the other half is for preheating), this gives a total energy variance of up to +/-25% perbrew.

Figure 20Specific energy recorded for wort heating of one product at one site over a month for a site with timedboils

Because the rate of heat input and boil time are constant the specific energy of the boil varies according to other

inconsistencies such as brew volume. For example, if the boil was based around the actual volume of beer

starting in the kettle the energy delivered would be on a quantified basis.

The second brewery monitored controlled its kettle based on calorific input (heat energy input level as a function

of product volume and desired boil-off), rather than timed controls (boiling the wort for a fixed time and then

testing for volatile removal level). The variance in specific energy for one product using a calorific controlled boil

over a month is shown inFigure 21 below. The amount of energy input per hectolitre of product is visibly much

more consistent.

Note that the different average specific energy shown in Figures 20 and 21 are not material here, since kettle

configuration and boil-of level vary between the two sites. The relevant finding is that a calorific (or specific heat

input) controlled boil gives a more consistent specific energy compared to time control, and offers a potential

energy saving through the avoidance of over provision of heat.


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Figure 21: Specific energy recorded for wort heating of one product at one site over a month for a site with heatinput controlled boils

3.1

3.12

3.14

3.16

3.18

3.2

0 20 40 60 80

kWh/hl


Another possible cause of the inconsistency seen in Figure 20 could be burn-on, which reduces the efficiency of

the calandria (fouling). However the kettles monitored were both cleaned weekly and if there had been burn-on

then within each week a consistent pattern of increasing energy consumption would have been seen, which it

was not. As we did not have alternative data to identify the burn-on status of the kettle we cannot make any

further judgements on this possible variable, but it seems unlikely from the data collected.

For the site that has a varying heat input (Figure 20), the boils with the least specific energy are currently deemed

acceptable, inferring that the boils with higher specific energy are using more energy than is necessary. It is

therefore reasonable to assume that moving to a system that operates on calorific controlled boils will reduce the

variance in heat input, and result in an overall reduction in energy consumption though the avoidance of over

provision of heat.

If a kettle with a timed boil-off could be re-programmed to provide heat on a calorific controlled approach, then

the amount of energy needed for evaporation could potentially be reduced by as much as 25% from the average

for a site where the boil off is around 3.5%. For sites with a higher boil (say 7% boil off) the fraction of total kettle

energy needed for evaporation will be higher at 64% as more energy is needed to drive off more wort compared

to the pre-heat energy, so the potential saving by moving from a time-based to calorific controlled boil-off will be

greater.

4.3 Best practice process optimisation opportunities

4.3.1 Areas of opportunity

There are several methods in which the energy necessary to carry out these processes can be reduced. All of

the following opportunities have been carried out in one form or another by international brewers and have beenproven to work without detrimental effects to the quality of the beer. We recommend that if any of these


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4.3.2 Impact on the UK brewing sector

Due to the variations in brewing techniques across companies, sites and product types it is difficult to estimate

with any accuracy the overall impact potential of the above measures across the UK brewing sector. The

following opportunities have been quantified using data from the monitored sites to act as a baseline for the

current industry position.

From the monitoring and analysis carried out on the data collected on kettle energy use we have shown that the

energy used can be accurately modelled to within 7 % in terms of specific energy consumption (see loss bridges

inFigure 13 and Error! Reference source not found.). The figures below demonstrate the effect of changing

the key wort stabilisation variables and give an indication of the potential savings available for these changes.

Reduction in boil-off: For every 1% that boil-off can be reduced in the kettle, the specific energy needed to

boil the wort can be reduced by 0.63 kWh/hl, which results from less energy being used for the latent heat of

evaporation, through evaporating 1% less of the total beer volume. For a gas-fired 2Mhl per year brewery this

works out as approximately 1.85p/hl reduction in the heat costs or a total site energy cost reduction of

37,000 per annum. If we assume that ale brewers use an average boil-off of 7.5% and that the bigger lager

and mixed brewers have an average boil off of 5%, bringing the entire sector down to a common baseline

boil-off of 3.5% would yield a sector carbon emissions reduction of around 2.5%. Through this reduction in

heating fuel, the equivalent average carbon emissions reduction per site would be 337tCO2 per year, for a

notional 2Mhl site.

Increase in high gravity brewing: For a kettle where the input temperature is 75C and there is a 3.5% boil-

off (similar to one of the breweries monitored as part of this project), we have looked into what difference a

change in the final gravity dilution of the beer will have on specific kettle energy consumption. Through

increasing the final gravity dilution less wort has to be processed (heated and evaporated) in the kettle for the

same amount of beer packaged.

Across the sector, it appears that lager brewers already have reasonably high HG dilution rates of 35% to 50%.

The ale brewers we spoke to appear to have lower rates, on the order of 10%, and the biggest opportunity for

change exists here. However, if the large breweries were able to make a further incremental increase in HG rate

then a significant impact could be made across the sector.

For every 10% increase in the final gravity dilution of the beer at an ale brewery the specific kettle energy can be

reduced by 0.73 kWh/hl. If we extrapolate an increase from 10% HG dilution to 50% HG dilution this equates to a

sector carbon saving of approximately 1.4% (just for the smaller, mostly ale-producing sites).

For a 2Mhl brewery this equates to a 31,000 annual energy cost saving and an annual carbon reduction of 275

tCO2. If the brewery had a higher boil-o

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