General Overview : Mash Side Details
By: Jason McCammon
With: Mike Smith
Typically a combination of milled grain and water where the mash is heated.
Common mashing steps include: Gelatinization
Liquefaction
Saccharification Or SSF (Simultaneous Saccharification and Fermentation)
Breaking down starch is most commonly accomplished with enzymes.
Mashing
Mashing, Mashing…
This To that.
What are Enzymes?
Active protein molecules (non-living)
Created by almost every living thing.
Present in saliva, stomach, etc.
Also called Koji Fermentation Semi-Solid Maintain 50% H2O
Enzyme Production
Submerged Fermentation
Solid State Fermentation
Very similar to a distiller’s fermentation.
Enzymes are proteins that act as Catalysts.
As such they do not get used up in the reaction.
Important factors are: pH, temperature, and substrate concentration.
Enzyme Properties
What do they look like?
3-D Structure
Conversion of starch to sugar.
No sugar = no fermentation = no alcohol
Other enzymes can be of assistance depending on the situation at hand.
Cellulase, Protease, Beta-Glucanase, Pectinase, etc.
Common sources of enzymes are malted grain, or commercially purchased enzyme.
How Can Enzymes Help?
Infusion Mashing
Typical style used for beer or scotch style whisky
Malted barley (or malted grain) is majority of grain bill.
Malt has its own enzymes to convert starch.
Infusion Mashing
This is a “two in one” process, as malt has both beta-amylase and alpha-amylase available to convert starch into sugars.
Easier method to get good results.
When using malt as a minority to convert the whole mash, be mindful of the DP (Diastatic Power) of the malt.
Malt is an exception, not the rule.
As distillers, it is in your best interests to know more about starch conversion
Infusion Mashing
The process of extracting the starch in grain into water, allowing us to begin the breakdown process of starch into sugar.
The more finely ground the grain is, the easier the gelatinization will be.
Must happen in the presence of water and heat to encourage water uptake
Gelatinization
Gelatinization table
Various Grains Temp range (oC) Temp Range (oF)
Wheat 58-65 135-149
Barley 52-60 125-140
Rye 55-70 131-158
Rice 68-78 154-172
Sorghum 68-78 154-172
Oats 58-72 135-162
Corn (generic yellow) 65-75 149-167
Millet 56-70 132-158
Different grains have different common gelatinization temperature ranges.
If the grain was pre-modified, it will be easier to hydrolyze the starch
i.e. Malt, Rolled grain, Flaked grain, etc.
Higher temps will increase rate of gelatinization
Gelatinization
Starch is present in two major forms.
Amylose – straight chains of glucose
Amylopectin – branched chains of glucose
The branched chains (α-1,6 bonds) cannot be broken by “regular” enzymes.
Starch Properties
v
Alpha – 1,6 bond
Alpha – 1,4 bond
The stage where the gelatinized starch is broken down by an alpha-amylase (typically) into dextrins.
Dextrins = random sugars (small chain to long chain)
Alpha-amylase – endo (interior) amylase that cuts interior α-1,4 glycosidic (glucose-glucose) bonds randomly.
Liquefaction
Liquefaction
Alpha-amylase
Beta-amylase
The pH plays a large role in optimal liquefaction.
Adjust as necessary for best enzyme activity.
There are three different kinds of alpha-amylase available to distillers currently.
Low temp (80 – 135 F). pH = 4.0 – 6.0
Med temp (120 – 165 F). pH = 4.5 – 7.5
High temp (175 – 190 F). pH = 5.6 – 6.5
Liquefaction
This step comes after liquefaction, it is the further breakdown of dextrins into small sugars that can be fermented by yeast.
Is usually accomplished at lower temperature ranges
Malted Grain Beta-amylase (130-145oF avg)
Exogenous Beta-amylase (80 – 140oF avg)
Primarily produces maltose sugars
Glucoamylase (80 – 140oF avg)
This is a different amylase. Instead of producing maltose, it will produce glucose.
Has alpha -1, 6 activity to degrade amylopectin. Sugar
Saccharification
Saccharification
Glucose Maltose (glucose-glucose)
Saccharification
Necessary step to produce sugars small enough for yeast to eat.
Beta-amylase will leave residual sugars.
Glucoamylase can produce up to a 95% fermentable mash
Old Ways – Best Ways?
Other sources of fermentable sugar are available and can produce excellent spirits.
There are less common starch sources like Agave or Jerusalem artichokes that store their starch as “Inulin” instead of amylose/amylopectin.
Many of the more popular spirits will be made from the regular starch sources. Due to laws and cost.
Corn, wheat, barley, rye, rice, millet, sorghum, etc.
Starch isn’t Everything
Alternative Sugars
Most fruits have their sugars in an available form as either fructose, glucose, or sucrose.
Notable exceptions are Apples and Pears
Most fruit could do with a mild pectinase treatment to enhance extraction/reduce viscosity.
Exogenous pectinases work well at native pH
Some fruits require pH adjusting (acidify) to prevent spoilage and enhance fermentation.
Fruit Mashes
Anything that has to do with directly fermentable sugar.
Table sugar, molasses, agave syrup, honey, etc.
pH will need to be adjusted and maintained
Step nutrient and sugar additions are highly recommended
Sugar Mashes
Various Starch/Sugar Sources...
Highly recommended for distillers as it promotes local economy, reduces costs(in some cases), etc.
Can work with local farmers to get them to grow what you want and make a spirit that abides by state sourcing laws
Local Grain Sourcing
Recommend establishing some form of testing to better predict results from each new batch of grain.
Problems can be large, so can benefits
Crop variation
Farm variation
Good option, but be mindful of the whole situation.
Local Grain Sourcing
Local Grain Sourcing
With few exceptions, mashing will require these steps
Gelatinization
Liquefaction
Saccharification
Getting the yields and profitability that you want will require measurements, excessive note taking, and the ability to troubleshoot.
Recap
Low Starting Gravity(Brix)
Was there a pH test of the mash?
Were there sufficient enzymes in the mash to convert the starch to sugar?
Was the mash held for long enough for them to work?
Was the starch sufficiently gelatinized at the beginning?
Was there enough grain in that amount of water?
Was an Iodine test for starch presence done?
How was the gravity/Brix measured?
Troubleshooting - 1
High Finishing Gravity(Brix)
What was the sugar source in the mash?
Starch from grain, glucose, molasses, malt, etc.
Was an Iodine test for starch done (if necessary)?
Were possible unfermentable sugars added?
Was there a “saccharification” step (if necessary)?
Did the fermentation behave erratically?
Troubleshooting - 2
Low Extractions
Iodine Test for Starch?
Was the pH of the mash checked?
Sufficient enzyme content? (Malt or exogenous)
Was the grain milled efficiently?
Sufficient agitation?
Was the mash lautered or transferred wholesale?
How hot did the mash get? And for how long?
How trustworthy is the thermometer?
Troubleshooting - 3
Stuck Fermentations
What is the mash material?
Were yeast nutrients used?
Was enough yeast pitched?
Was the yeast strong enough to handle the mash/osmotic pressure?
What are the cleaning methods in the distillery? How often are vessels cleaned and sanitized?
What was the fermentation temperature (or range)?
Open or Closed Fermentation?
Troubleshooting - 4
Theoretical Sugar Yield
1668 lbs. of wheat starch at 95% starch content. Using 500 gallons of water.
1668 x .95 = 1585lbs of starch = 1585lbs of sugar (assuming no losses etc.)
Impossible to achieve, but for the sake of calculations...
1585lbs sugar/4170lbs water = 38% sugar solution (roughly) or 38.34g/100mL (exactly)
This would result in about a 19% abv if fully converted
Calculating yield
Theoretical Ethanol Yield
Using previous info…
1585lbs of sugar x 51.1% (Gay-Lussae Yield) = 809.9lbs of ethanol
809.9lbs of ethanol x 1gallon/6.58lbs ethanol = 123.1 gallons ethanol (200 proof)
123.1 gallons ethanol x 95% yield = 116.9 gallons ethanol (200 proof)
This is the efficiency yield, obviously not a real #
Calculating Conversion
Theoretical Calcs
Any Questions? Or should we get Distilling?
Finish