District NW Spring meeting 2012

Reducing Fermentation Variation

Peter Bouckaert New Belgium Brewing Co

Factors affecting fermentation variation Variables: •  Yeast:

amount, vitality, viability, generation, time of addition,…

•  Fermenter conditions: Number of brews, temperature tank, KO temperature, outside temperature,….

•  Fermentation heat up rate •  Nutrients:

Sugar profile, aeration, minerals, vitamins, FAN,…

Variables yeast’s past: •  Yeast storage time and

temperature, •  length of previous

fermentation, •  fermentation cool down

rate •  Fermentation heat up rate •  Anomalies

Project Goal

•  Problem: Fermentation times are too variable

•  Key measure: Standard deviation of fermentation time of beer1 excluding generation 1 fermentations

•  Goal: Standard deviation <3 hrs

•  Other benefits: Beer consistency, tank turn around time, other beers will benefit from learning on beer1

Project drivers:

•  Postponing buying new fermenters – Less fermentation variation, easier planning

•  Manufacturing Execution System (MES) implementation – What date to collect from the process?

•  Reduce frequency of diacetyl measurement if fermentations are more predictable.

Process:

yeast storage 3C

Propagation Brew

Ferment: Heat up KO --> 20C data for prediction Ferment to end of VDK rest to be predicted Cool down

Fermenter queing

Fermenters available

centrifuge/chill -1C

yeast storage 3C

Propagation

Brew

Ferment: Heat up KO --> 20C data for prediction

Ferment to end of VDK rest to be predicted

Cool down

Fermenter queuing

Fermenters available

centrifuge/ chill -1C

Measurements defined

•  Key measure: Beer1 fermentation time from start of first brew coming in the fermenter (Knock-out or KO) until VDK (vicinal diketones) are low enough to cool down.

•  Method of measurement: Through process historian of PLC, later transferred to Manufacturing Execution System Except VDK (see next slide)

•  Measurement variation: 12 minutes variation between operators - OK

VDK measurement Measurement System Analysis: Operator, range, sample prep

Prediction curve beer1: Brand specific

Source Variance Standard Deviation % Contribution Total Measurement (Gage) 1726.17857 41.54730522 1.15% Repeatability 165.5 12.86468033 0.11% Reproducibility 1560.67857 39.50542458 1.04% Operator 393.904762 19.84703408 0.26% Oper * Part Interaction 1166.77381 34.15807093 0.78% Product (Part-to-Part) 147826.472 384.4820831 98.85% Total 149552.651 386.720378 100.00%

USL LSL Precision to Tolerance Ratio Precision to Total Ratio 0.107435 Resolution 13.0

-5

0

5

10

15

20

25

0 200 400 600

time

to T

-dow

n (h

ours

)

VDK (ppb)

VDK reduction slope > generation 1

yeast pitched measurement analysis

Cell count Slurry volume (spin down) Source Variance Standard Deviation % ContributionTotal Measurement (Gage) 37419.18 193.44 7.91% Repeatability 31346.80 177.05 6.63% Reproducibility 6072.38 77.93 1.28% Operator 6072.38 77.93 1.28% Oper * Part InteractionProduct (Part-to-Part) 435537.50 659.95 92.09%Total 472956.67 687.72 100.00%

USL 2000.00LSL 0.00Precision to Tolerance Ratio 0.58Precision to Total Ratio 0.28Resolution 4.8

Source Variance Standard Deviation % ContributionTotal Measurement (Gage) 5.32 2.31 0.86% Repeatability 5.00 2.24 0.81% Reproducibility 0.32 0.57 0.05% Operator 0.00 0.00 0.00% Oper * Part Interaction 0.32 0.57 0.05%Product (Part-to-Part) 612.69 24.75 99.14%Total 618.01 24.86 100.00%

USLLSLPrecision to Tolerance RatioPrecision to Total Ratio 0.09Resolution 15.1

3x increase in resolution

Viability MBà resolution 1 L

Base line measurement

std. dev 720hl

average 720hl std. dev. 1440 hl

average 1440hl

0

10

20

30

40

50

60

70

80

90

100

F time KO to 24C 18to24C at 24C

14.6 14.8

6.5 9.7

95.6

54.7

29.2

38.3

10.5 7.5

5.1 5

91.6

48.2

23.4

39.2 std. dev 720hl

average 720hl

std. dev. 1440 hl

average 1440hl

Ferm

enta

tion

time

(hou

rs)

Trivial Many à Vital Few Variables: •  Yeast:

amount, vitality, viability, generation, time of addition,…

•  Fermenter conditions: Number of brews, temperature tank, KO temperature, outside temperature,….

•  Fermentation heat up rate •  Nutrients:

Sugar profile, aeration, minerals, vitamins, FAN,…

Variables yeast’s past: •  Yeast storage time and

temperature, •  length of previous

fermentation, •  fermentation cool down

rate •  Fermentation heat up rate •  Anomalies

Is this yeast vitality? DOE Pro

Sigmazone®

Modeling

Voilà Voilà

Only variables within current fermentation

fermentation:variable abbreviation unit variable abbreviation unityeast pitch volume Vol/br hectoliter length of fermentation pFVt hrcell count cells cells/ml time until VDK down pVDKt hrviability viab % yeast storage time Ystime hrgeneration genKO temp. to 16C t to 16C hr KO temp. to 16C pt to 16 hr16C to 18C 16 to 18 hr 16C to 18C p16 to 18 hr

exothermic 18C to 20 C 18 to 20 hr 18C to 20 C p18 to 20 hrtimes KO temp. to 20C t to 20 hr KO temp. to 20C pt to 20 hr

T in fermenter KO1 T1st Cstart of T in fermenter KO2 T2nd Cfermentation T tank T tank Cconditions number of brews #brews

yeast related

previous fermentationcurrent fermentation

0.0 0.5 1.0 1.5 2.0

vol/br

T2nd

t to 16

16 to 18

T1st

cells

18 to 20

Ttank

t to 20

gen

viab

#br

within fermentations

Compilation from modeling historical data with DOE Pro® from Sigmazone ®

Variable included from previous fermentations

Individual variables less important than their interactions!

0.0 0.5 1.0 1.5 2.0

T2nd16 to 18pt to 20pVDKtt to 20

T1st18 to 20

t to 16Y vol/brYsttime

pFVtcellspT5

pT10pT3

p18 to20generation

T tank#brews

with previous fermentation

fermentation:variable abbreviation unit variable abbreviation unityeast pitch volume Vol/br hectoliter length of fermentation pFVt hrcell count cells cells/ml time until VDK down pVDKt hrviability viab % yeast storage time Ystime hrgeneration genKO temp. to 16C t to 16C hr KO temp. to 16C pt to 16 hr16C to 18C 16 to 18 hr 16C to 18C p16 to 18 hr

exothermic 18C to 20 C 18 to 20 hr 18C to 20 C p18 to 20 hrtimes KO temp. to 20C t to 20 hr KO temp. to 20C pt to 20 hr

T in fermenter KO1 T1st Cstart of T in fermenter KO2 T2nd Cfermentation T tank T tank Cconditions number of brews #brews

yeast related

previous fermentationcurrent fermentation

Time from cooling on until certain beer T reached

Single secondary parameter: Green beer cool down time variation

cooling rate, time (hrs) to reach 10C

UCL=17.387

LCL=4.22

CEN=10.804UCL=12.158

LCL=7.602

CEN=9.88UCL=11.373

LCL=7.9854

CEN=9.6792

0

2

4

6

8

10

12

14

16

18

20

1844

218

46418

47918

51118

53718

558

1858

318

62218

63918

67018

69518

72318

746

1877

818

79818

82418

85618

87818

90218

928

1895

518

99019

02819

04619

06419

10519

141

1916

219

19919

23219

25319

27919

30019

320

1935

019

36519

40019

46919

56819

59819

666

Different group of fermenters used

Design of Experiments (DOE)

•  Two variables –  T of knock out

•  (1)-0.5&+1C, (2)+1&+2C –  Yeast pitching rate.

•  (1)+/- 16.7%, (2)-0,-16.7% –  5 repetitions randomized –  Same tank size/6 brews

•  Confounding variables: –  Yeast harvests from tests

•  Time bound: outside T 1.2

1.4

1.6

1.8

2

2.2

2.4

13 13.5 14 14.5 15 15.5 16 16.5 pi

tchi

ng r

ate

KO T (°C)

DOE 1

DOE 2

DOE 1: Data analysis

y = -0.1186x + 4685.5 R² = 0.40222

10.0

12.0

14.0

16.0

18.0

20.0

22.0

14.0

14.5

15.0

15.5

16.0

16.5

8/16 8/26 9/5 9/15 9/25 10/5 10/15

Tem

pera

ture

in F

V lo

wer

pro

be a

fter

KO

3 (C

elsi

us)

all

LL

LH

HL

HH

FV T

Linear (all)

Linear (FV T)

65

70

75

80

85

90

8/21 8/31 9/10 9/20 9/30 10/10

ferm

enta

tion

time

(hr)

all

LL

LH

HL

HH

Linear (all)

DOE 1 results: closer look

1.2

1.4

1.6

1.8

2

2.2

2.4

13 13.5 14 14.5 15 15.5 16 16.5 pi

tchi

ng r

ate

KO T (°C)

DOE 1

DOE 2

Shorter fermentation time

Less variation 13.5 13.83333333

14.16666667 14.5

14.83333333

0.0

1.0

2.0

3.0

4.0

5.0

6.0

1.5 1.6 1.6 1.7 1.8 1.8 1.9 2.0 2.0 2.1

KO temperature ( C)

stan

dard

dev

iatio

n (h

ours

)

pitch

Fermentation time S-hat Surface Plot KO T vs pitch

5.0-6.0 4.0-5.0 3.0-4.0 2.0-3.0 1.0-2.0 0.0-1.0

What did change?

•  KO T à T in fermenter (yeast T, PID) •  Increased KO T for 1 generation •  Ferment in certain set of fermenters •  Stopped using viability through Methylene

Blue à heat up time •  Spin down lab centrifuge test for pitch •  Pitch slightly less •  KO T used for seasonal fluctuations

How will you hold the gain? Control Charts / QA group

UCL=90.315

LCL=60.926

CEN=75.62

UCL=91.826

LCL=64.816

CEN=78.321

USL=95

LSL=70

50

55

60

65

70

75

80

85

90

95

100

3000

8 30

023

3003

7 30

047

3004

6 30

071

3008

1 30

098

3010

4 30

125

3014

0 30

158

3017

2 30

178

3019

2 30

198

3021

7 30

226

3024

2 30

256

3026

7 30

280

3028

9 30

309

3031

5 30

324

3033

1 30

342

3035

3 30

367

3040

6 30

413

3042

0 30

434

3046

1 30

482

3048

8 30

545

3055

4 30

582

3061

1 30

628

3064

6 30

655

3067

3 30

697

3072

3 30

739

3076

4 30

772

3079

8 30

809

3082

4 30

833

3084

5 30

857

3086

8 30

877

3087

7 30

892

3091

9 30

922

3095

9 31

014

3103

2 30

164

FT fermentation time (hours)

What did we gain?

•  $8 M in 2007 à $3.7 M in 2010 – Queuing and fermentation variation!

•  Stopped inaccurate measurement: – Methylene Blue – Cell count

•  Automated measurements through MES – Heat up rate of fermenters:

•  Early warning that fermentation is “off” •  Actions: no harvest source, blending, KO T

change

Reducing Fermentation Variation

Peter Bouckaert New Belgium Brewing Co