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 :