practical brewing enzymology

MBAA – Rocky Mountain District

Coors Brewery Institute

Practical Brewing EnzymologyTobin L. Eppard

Coors Brewing Company

www.coors.com

Rocky Mountain District - MBAAMay 11, 2005



• What is in (and out) the box for today– A Brief Primer on Enzymes – Malting processes– Mashing processes– Practical Brewing Implications– Q&A Session


Coors Brewery Institute Historically speaking..

• 1783 – Spallanzani noted a non cellular breakdown of meat by gastric juices

• 1814 – Kirchoff, wheat paste converted starch to sugars…• 1878 – Kuhne suggested Enzyme = “In Yeast”• Catalytic Activity

Substrate

Product(s)

Enzyme/SubstrateEnzyme


Coors Brewery Institute What are Enzymes?

• Protein

• Structure is specific to function

• How is shape determined?– Functional groups– Amino acids….


Coors Brewery Institute What are Enzymes?

• Primary Structure

• Secondary Structure

• Tertiary Structure

• Quaternary Structure


Coors Brewery Institute What do they do?

• “Spontaneous” Chemical Reactions– Energy Barriers, EA - Energy of Activation

• Reduction of EA (G) by as much as 1015

Ene

rgy

Lev

el

C

A

B1

B2

EA of Enzyme Catalyzed Reaction



Enzyme Biochemistry

• Lock and Key Model

Substrate

Enzyme/Substrate Complex

Product(s)

EnzymeEnzyme



Enzyme Biochemistry

• Enzyme “Process” in Biologic SenseNEED Energy

DNA

RNAAMINO ACIDS

Ribosome

1 o Sequence

2 o Sequence

3 o Sequence

4 o Sequence

Yeast

A-T-G-A-C-GFunctional Protein (Enzyme?)

Inhibition



Enzyme Biochemistry

• Factors Influencing Enzyme Rates:– Endo vs Exo enzymes– pH– Temperature– Products/Inhibition– Kinetics


Coors Brewery Institute Enzymes in Malting

What’s going on in barley?

Thousands of enzymes…

Cellulases

Proteases

Amylases


Coors Brewery Institute Enzymes in Malting

Barley Modification

Pictures: David A. Thomas, Coors Brewing Company and Kunze, Technology Brewing and Malting


Coors Brewery Institute Enzymes in Mashing

Mashing• Solubilize starches

and Amino Acids/peptides• Starches to reducing sugars• Denature protein


Coors Brewery Institute Brewing Enzymes

Enzyme Action Opt. Temp pH Amylase 67C 5.2

Amylase 62C 5.5

Proteases < 52C 5.5

Glucanase 40 – 52C 6.0

Glycosidic -1,4 Endoamylase

Glycosidic -1,4 (Non-reducing end C-4) Exoamylase

Solubilize Proteins and Polypeptides (FAN) Endo and Exoproteinases

Glycosidic β-1,4 and β-1,3 Gum/Cell walls, reduction in wort viscosity Endoglucanase



*Exogenous Brewing Enzymes

Enzyme Action Opt. Temp pH Amylase (HS) ~ 67C 5.2

Amyloglucosidase ~ 60C 5.5

(AMG) Glucanase 40 – 52C 6.0

Pullulanase - -



Glycosidic β-1,4 and 1,3 Gum/Cell walls, reduction in wort viscosity Endoglucanase

* - Not an exhaustive list, contact Novo or Genencor for more information

Glycosidic -1,6 (Random) Endoamylase



Practical Aspects of Brewing Enzymes…


Coors Brewery Institute First Aide Kit

Extract Production– Starch Gelatinization Temperatures

• Well Modified Malt(s)

– High DP malt OR • Heat stable Alpha Amylase and Beta Amylase

– Adjunct usage rates • Dilution of DP..



Extract Separation– Maximize Beta Glucanase (what little is

there)• Consider, lowering your first mash-in

temperature

– Exogenous Beta Glucanase– Minimize shear forces



Wort Fermentability (more or less?)– Exogenous Alpha Amylase, Beta Amylase– Amyloglucosidase, Pullulanase– Slightly lower conversion hold (64-65C)– Slower ramp from conversion hold to mash

off (2ºC/min vs. 1ºC/min)– Consider the use of kettle adjuncts like

HFCS… @DE of 95%



Beer Filterability– Exogenous Beta Glucanase– Maximize Trub Formation (finings, boil)– Maximize cold maturation (if possible)– Add DE filtration first, before sheet filtration (if

possible)– Reduce shear forces– Yeast flocculation issues– Secondary finings (isinglass) and

hydrogels/xerogels…

Pitures: Bill Simpson (Cara Technologies)



Beer Foam– Maximize solubilization of HMW Proteins

• Consider raising your initial mash in temp (60-62C)

– Hops +– Viscosity (higher PG)+– Gas +– Yeast Enzymes

• Stress and high gravity – hydrophobic polypeptide reduction


Coors Brewery Institute Quality System

• Most important of all…

Set Malt Quality parameters and hold supplier accountable to meet them

– Extract - S/T or Kohlbach– Viscosity - Total Protein– Color - Friability– DP



Final Notes on Exogenous Enzymes:– Safety Concerns (handling)– It’s a Soup of a larger cast of

characters• Side Reactions

Discussion?

Pictures and Acknoledgements:

David A Thomas – Barley grain modification SEM(s)

Dr. Bill Simpson – CaraTechnologies, UK

Mathewson, Paul R. Enzymes – Practical Guides for the Food Industry Eagan Press Handbook Series, St. Paul Minnesota, USA 1998 (sponsored by the American Society of Brewing Chemists)

practical brewing enzymology

Documents