24/05/2017Titre 1
EBC wort turbidity :
Nature and impact of malting and
brewing process
Patrick Boivin & Sophie SCHWEBEL
L47 (88)
Study context�EBC Method 4.5.1 : Extract of malt : Congress mash
�This procedure is used for numerous malt quality parameters
EBC wortViscosity
Colour pH
Soluble
proteins
Free amino
nitrogen contentExtract of
malt
Odour
Saccharification
rate
Turbidity
Material and methods�EBC Method 4.5.1 (50 g malt fine grind + 200 ml water + 100 ml water at 70 °C)
�Turbidity measurement at 25° (HACH 2100 AN)
MILLING BREWING FILTRATION TURBIDITY
Study context
Is the EBC wort turbidity tightly
linked to the haze of beer ?
� Which compounds are responsible for this
EBC wort turbidity ?
� How can we manage their evolution during
malting and brewing process ?
Presentation Overview
Impact of malting process on
EBC wort turbidity
Identification of compounds
responsible for EBC wort turbidity
Impact of mashing diagram on
EBC wort turbidity
1
2
3
Biochemical changes in barley during
modification
EMBRYO
water
oxygen
GAS
GAS
Enzymes
Enzymes Enzymes
Enzymes
CO2
heat 1: water uptake by the micropyle: embryo is hydrated
2: oxygen uptake in the kernel: embryo breaths
3: hydration of endosperm
4: embryo products gibberellins that migrate to aleurone layer
5: gibberellins activate aleurone layer that will produce hydrolytic enzymes
6: hydrolytic enzymes migrate to starchy endosperm
7: β-glucanases hydrolyses endosperm layer (kernel becomes friable)
8: proteases act on protein: production of soluble proteins and FAN 6
Steeping step
Germination step
Enzymes production
Enzymes diffusion
Enzymes action
Turbidity of wort & databases
�Databases exploitation
�CBMO: French malting barley qualification
• 1 barley variety > 1 malt batch
• 20 parameters on malt
16/06/2016
Turbidity of wort & databases�CBMO Database
�PCA with 14 malt parameters :
� In this database : not possible to explain wort turbidity with malt parameters
� Too many barley varieties 16/06/2016
Turbidity of wort & databases
�CBMO Database
�PCA for SEBASTIAN
pH, β-glucans
�PCA for ESTEREL
β-glucans, (α - amylase)
�PCA for VANESSA
Color, (β-glucans)Correlation (+)
Correlation (-) pHα- amylase16/06/2016
Impact of malting process�Methodology : Micromalting of barley according to several process
experimental conditions (~600g)
2-row spring barleyvarieties
• A
• B
• C
• D
4 steeping diagrams
• D1 : 10 / 20 / 7 (37h)
• D2 : 10 / 17 / 3 (30h)
• D3 : 8 / 15 / 3 (26h)
• D4 : 6 / 8 / 5 / 7 / 3 / 2 (31h)
Germination conditions
• 4 or 5 days
• Addition of Giberrellic acid
Kilning conditions
• CTPS like curing (up to 85°C)
• CTPS like curing (70°C max)
Impact of malting process
600 Kg IFBM MALTING PLANT
Cylindro-conical vessel Saladin box Single desk kiln
Impact of malting process (Steeping)Conditions : 5 days of
germination, Kilning with
curing up to 85°C, without
addition of giberrellic acid
Diagram Air/Wet (h) Duration (h)
D1 10 / 20 / 7 37
D2 10 / 17 / 3 30
D3 8 / 15 / 3 26
D4 6 / 8 / 5 / 7 / 3 / 2 31
�EBC wort turbidity depends on barley variety
�Effect of steeping process diagram
�Shorter steeping diagram (D3) > bad endosperm hydration > lower modification
> � turbidity
�Longer or optimized steeping > good endosperm hydration > good modification
(D4): � turbidity
13
Hydration of endosperm
Good endosperm hydration
Bad endosperm hydration
low quality malt
Steeping is a key step to produce a good malt
high quality malt
Impact of malting process (Germination)
�No impact of germination duration on turbidity (but � betaglucans content)
�Addition of giberellic acid seems to trigger the decrease of turbidity
(improve modification) more significantly
Giberellic acid (0,5 ppm)
Germination duration (days)
Conditions : D2, Kilning with
curing up to 85°C
Impact of Gas on wort turbidity
and others malt parameters
Malt analysismalt 6RH
without Ga3
malt 6RH with Ga3
Moisture (%) 4.7 4.4
Fine grind extract (% D.M.) 79.8 81.2
Color (EBC) 3.3 3.8
Boiled Color K.Z. (EBC) 5.0 6.9
Total protein (% d.m.) 10.00 9.9
Soluble soluble (% d.m.) 3.57 4.83
Friability (% flour) 86 96
Calcofluor % modification 98 99
Calcofluor %homogénéity 87 96
β -glucans (mg/l of wort) 169 38
diastasic power (WK m.s.) 330 360
α -amylase (UD 20°C m.s.) 34 55
Viscosity (mPa.s) 1.53 1.46
Free amino nitrogen (mg/l) 116 184
Fermentability (%) 81.5 84.3
Turbidity (EBC) 4.9 0.9
600 Kg IFBM
MALTING PLANT
Biochemical changes in barley during
modification
EMBRYO
water
oxygen
GAS
GAS
Enzymes
Enzymes Enzymes
Enzymes
CO2
heat
16
More Gas enzymes production
β-glucanases
α-amylases
proteases
Ga3
Ga3
Ga3
Endosperm modification
17
STARCH TRAPPED
& HARD KERNEL
FRED STARCH
& GOOD MODIFICATION
NO FREED STARCH
& BAD MODIFICATION
Impact of malting process (Kilning)
�No significant impact of curing temperature on turbidity
Conditions : D2, Kilning
with curing at
to 70°C
to 85°C
0 3 6 9 12 15 18 21 2440
50
60
70
80
90
100
110
120
130
140
150
160
Kilning time hrs
Relative
enz
yme a
ctivity Alpha-
amylase
Beta-amylase
Beta-glucanase
Endopeptidase
Carboxypeptidase
enzyme
Kilning: Enzymes activities
19
Impact of malting process
�EBC wort turbidity can be very different according to barley variety
�EBC wort turbidity is tightly linked to grain modification
�During the malting process, EBC wort turbidity is influenced by :
• the steeping diagram: hydration of endosperm
• the addition of giberellic acid during the germination step by
improving some enzymes production
�Effect on β-glucans to keep in mind
Protein based
turbidity ?
Starch based
turbidity ?
Identification of compounds
EBC wort
Polysaccharide
based turbidity ?
Mineral based
turbidity ?
Identification of compounds
�Turbidity of EBC wort depends a lot on barley variety
�To identifiy haze compounds, different barley varieties were used
0
2
4
6
8
10
12
14
16
18
20
Variety A(2014)
Variety A(2015)
Variety B(2014)
Variety C(2014)
Variety D(2014)
EB
C w
ort
tu
rbid
ity
(UF
EB
C)
Turbidity of wort
�Centrifugation to collect « haze »
EBC congress mash
EBC wort
Malt
supernatant Pellet fraction
AnalyzesAnalyzes
Centrifugation
Electrophoresis of pelletsDiagram D1 D1 D1 D2 D2 D3 D3 D4 D4
Giberellic acid (ppm) 0 0 0.5 0 0 0 0 0 0
Germination (days) 4 5 4 4 5 4 4 4 4
Kilning CTPS CTPS CTPS CTPS CTPS CTPS 70°C CTPS 70°C250150100
75
50
37
25
20
15
� Protein profile appears not to be modified with malting diagram or germination times
Diagram Air/Wet (h) Duration (h)
D1 10 / 20 / 7 37
D2 10 / 17 / 3 30
D3 8 / 15 / 3 26
D4 6 / 8 / 5 / 7 / 3 / 2 31
� Protein A (~ 40 kDa) seems to be present in pellet (= Z ?)� Protein B (~45 kDa) modified with giberellic acid
Identification of haze compounds
�Arabinoxylan and mineral no impact
�β-glucan difficult to conclude
�Protein profile appears not to be modified
Turbidity measurement
Identification of compounds
EBC Wort
�Methodology to determine a potential starch based turbidity:
27
starch
STARCH
GELATINIZATION OF BIG GRANULES: 62-65°C
: 63-65°C
: 72-74°C
β-amylase
α-amylase
FERMENTABLE SUGARS STEP
DEXTRINS STEP
Limit dextrinase
Identification of compounds
By adding a rest at 63°C, the
ß-amylase and limit dextrinase
activities which degrade starch is
more efficient !!
EBCm Wort
Identification of compounds
�Strong reduction of turbidity with the rest at 63°C
�The EBC wort turbidity is partly starch-based for these samples
�Variable according to the variety
Decrease of turbidity
from EBC wort to EBCm58% 64% 82% 67% 53% 32%
EB
C W
ort
EB
Cm
Wo
rt
Gelatinization temperature
CROP
Gelatinization
Temperature °C
2014 61-63
2015 62-65
Turbidity measurement
EBCm Wort
Identification of compounds
EBC Wort
�Methodology to determine a potential starch based turbidity:
EBCa Wort
Identification of compounds
We assessed the gelatinisation
temperature (RVA, Rapid Visco
Analyser) of each sample to be sure
that all the big starch granules are
gelatinazed
Identification of compounds
�Hypothesis : the higher gelatinization from the variety D (2014 and 2015)
could explain the less efficient amylolyse
�Decision : Adapt the additional rest at 65°C instead of 63°C
Decrease of turbidity 58% 64% 82% 67% 53% 32%
EB
C W
ort
EB
Cm
Wo
rt
Gelatinization temperature 62,7°C 63,7°C 64,9°C 64,4°C
Identification of compounds
�A temperature above the gelatinisation temperature allows a
decrease of turbidity
� the EBC wort turbidity is not improved for the variety D (2015)
EB
C W
ort
EB
Cm
Wo
rtE
BC
aW
ort
Decrease of turbidity
from EBCm to EBCa13% � 19% 26% 5%
Optimum temperature and pH of
amylolytic malt enzymes
pH
optimum optimuminactivati
on
Dextrinase
limite5.4 68
Amylolytic
enzymes
70-72
62-64
60-65
α-amylase 5.6-5.8 75
β-amylase 5.4-5.6 68
Temperature °C
Mashing regime
�EBC Mashing regime should be optimized
�For big starch granules gelatinization
�Optimum temperature and pH for amylolytic enzymes actions
Identification of compounds
�The principal component analysis
(PCA) shows that
�Diastatic power is strongly
negatively correlated to the
turbidity of the variety A (2014)
�Turbidity from variety D (2015)
seems to be explained mostly by
the presence of proteins and
beta glucans
-0,8
-0,6
-0,4
-0,2
0
0,2
0,4
0,6
0,8Moisture
Extract
Color
Total proteins
Soluble proteins
Kolbach Index
Friability
Viscosity
Beta glucans
Diastatic power
PCA correlation coefficientsVariety A (2014) Variety D (2015) 0
n=24 n=20
Identification of compounds
�To conclude
�Compounds involved in the EBC wort turbidity may not be similar
according to barley variety (protein- or starch-based…)
• Differences between varieties A and D
�Presence of starch may explain part of the EBC wort turbidity as
amylolytic activities are not well promoted in this type of diagram
• BUT in some cases, this starch-based turbidity could be removed
by using an adapted mashing diagram (rest around 63°C)
CORRELATION BETWEEN EBC CONGRESS
WORT HAZE AND BEER PROCESS & QUALITY
Semi-industrial wort and beer production
20 HL Brewing plant
Turbidity of wort� Information of IFBM data-base :
�Pilot trials from CBMO
• 1 malt batch => 1 brew => 1 beer
• 150 malt batches > 150 beers
• Mashing regime
40
45
50
55
60
65
70
75
80
0 15 30 45 60 75 90
Time (min)
Tem
pera
ture
(°C
)
50°C
64°C
74°C
78°C
Malt grits = 300 kg
Water = 950 kg
pH = 5.4+/- 0.1
Congress wort turbidity and
final haze of beer
wort turbidity and beer process
�No relation with mash filtration
�No relation with cold wort turbidity
� No relation with beer filtration
Take home message
�Turbidity analysis on EBC wort is not a good indicator to predict the
turbidity of an industrial wort and beer
� If still this parameter on some brewers specifications
�Impact of barley variety :
• Nature of turbidity can be different according to variety
�Malting process can influence EBC wort turbidity
• Poor modification of the barley leads to turbidity
– Optimization of steeping regime
– Ga3 if allowed by national regulation & brewers
Take home message
50 °C
63°C
75 °C
15 min
15 min
15 min
1°C / min
1°C / minfiltration
pH:5.4
filtration under pressure
sparging with water at 75°c
Tepral mashing & filtration
Modification of mashing regime and mash filtration
to be closed to industrial mashing regime
Thank you for
your attention !
with the support of :