Making Enzymes Work
For You
Randy Scorby
BJCP Continuing Education Director
and Grand Master II Judge
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Topics
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What are enzymes?
How did they get into my malt?
Limitations of enzymes
Enzymatic reactions
Factors that influence rate of
reactions
• Deactivating enzymes
• Mash considerations
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Topics
• Extract Efficiency
• Crushing Grains
• Malt Characteristics
– Diastatic Power
– Modification
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What are enzymes?
• Catalyst for biochemical reactions
• Non-living biomolecules that speed
up the rate of chemical reactions
• Proteins made up of several
thousand different amino acids
joined together
• The molecule the enzyme acts on
is the substrate, and the enzyme is
usually named after the substrate.
– Beta Glucanase acts on Beta
Glucans
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What are enzymes?
• The amino acid chain forms a
specific shape that is suited to a
specific job the enzyme must
perform
• The shape is somewhat fragile and
can be damaged by heat, agitation
or chemical attack, which will
render the enzyme unable to act as
a catalyst for the reaction
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Active Site
• Enzymes have a structure call an
active site. Only one substance
can fit into the active site; therefor it
is the only substrate that the
enzyme can work with.
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Active Site
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How did they get in my malt?
• Some enzymes are already
present in the barley (ß-amylases)
• Majority are produced during the
germination phase (α-amylases &
proteases)
• All enzymes needed for conversion
are present in the final malt.
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Outcome From Malting
-Develop enzymes that will reduce
starches and proteins during
malting and mashing
-Breakdown grain cell walls to
allow enzymes to start
modification, which means
appropriate breakdown of starches
and proteins in order for the malt to
be mashed properly
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Understanding the Mashing
Process
• By understanding and being able to
manipulate enzyme activity you can
control the fermentability of your
wort
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What’s happening in my mash
• Think of your mash as two distinct
operations
– Conversion of solid malted barley into
a liquid extract
– Recovering the sweet wort from the
spent grains
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Primary Mash Enzymes
• Alpha Amylase
– Breaks down large, complex insoluble
starch molecules into smaller soluble
molecules for Beta Amylase to work
on
– Stable in hot, thin mashes
– Results in fermentable sugars and
dextrin in a temperature range of
~145° to 158°
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Primary Mash Enzymes
• Beta Amylase
– Creates most fermentable sugars,
breaks down starch to create
maltose, glucose and maltriose
– Most active from 131° to 149°
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Factors that Influence Rate
of Reaction
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Enzyme Concentration
Substrate Concentration
Temperature
pH
Inhibition
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Enzyme & Substrate
Concentration
• Enzyme & substrate concentration
is mostly dependent on mash
thickness
• Although not critical, mash
thickness is still an important
consideration
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Thick Mash
• Thick mashes (1–1.25 qt/lb)
– Quicker starch conversion
– Better for protein breakdown
– Offers better protection for enzymes
• Less likely to be denatured by higher
temperatures
– More suited for step mashes as
enzymes are not denatured as fast by
temperatures increases
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Thin Mash
• Thin mashes (>2 qt/lb)
– Dilutes concentration of enzymes
– Slows conversion
– Leads to a more fermentable mash
as enzymes are not inhibited by a
higher concentration sugars
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Temperature
• Each enzyme has an optimum
temperature, the temperature at
which the enzyme is most active.
Below that temperature and the
enzymatic activity will decrease
until it ceases, too far above will
cause it to denature and no longer
function.
• Different enzymes become active at
different temperature ranges,
although
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some overlap
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Temperature
• At lower temps, the enzyme and the
substrate move slowly and collide
weakly, this is when the enzyme is
inactive and fails to work.
• When temps increase, both gain
more kinetic energy, which causes
them to move faster and collide
more.
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Temperature
• When enzymes reach their
optimum temp, they are most
active. As they pass through
optimum temps they begin to
denature, changing the shape of
the active site. When this occurs,
the substrate can no longer fit in
active site.
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pH Level
• Mash pH should fall within a range
of about 5.2 to 5.5 for enzymatic
activity
• Most mash pH levels fall within this
range, but can be adjusted if
needed depending on brewing
water
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Inhibition
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Too high or low temperature
Organic solvents
Unfavorable pH
Chelating agents
All of these can denature
enzymes
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Effects of Denatured Enzymes
• Higher terminal gravity
• Higher level of sweetness
• Lower alcohol content
Once an enzyme is denatured, or the
structure is destroyed, it can rarely be
renatured
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Denaturing
When stirring in grains into your
mash, remember that exposure to
very high heat even for a few
seconds before the mixture becomes
homogenous can work against you
to destroy fragile enzymes
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Mash Out
• One purpose is to denature
enzymes and preserve the
fermentable sugar profile.
• Temperature is raised to 170°
• Is this necessary for small batch
home brewers?
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Mash Out
• Benefits–Can make the wort more fluid
and prevent a stuck sparge
–Usually not needed with a thin
mash
–Works well when using wheat,
rye or oats
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Diastatic Power
• Enzymatic power of the malt, or
the ability to convert itself
• Diastatic refers to diastase
enzymes
• Listed on malt analysis sheet that
can typically be found on the
maltsters web site.
• Measured in °Linter
• 35-40 °Linter is needed for self
conversion
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Diastatic Power
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American 2 Row Pale Malt: 140 °Lintner
American 6 Row Pale Malt: 160 °Lintner
British Pale Malts: 40-70 °Lintner
Maris Otter Pale Malt: 120 °Lintner
Belgian Pale Malt (2 row): 60 °Lintner
German Pilsner Malt: 110 °Lintner
Munich Malt (10 SRM): 70 °Lintner
Munich Malt (20 SRM): 25 °Lintner
Vienna Malt: 50 °Lintner
Wheat Malt, German: 60-90 °Lintner
Wheat, Unmalted (flaked, Torrified): 0 °Lintner
Crystal Malt (all): 0 °Lintner
Chocolate Malt: 0°Lintner
Black Patent Malts: 0 °Lintner
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Diastatic Power
• The lower the Diastatic Power, the
longer it takes to convert
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Influence of the Mash
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Aroma
Flavor
Body
Overall Mouthfeel
Attenuation
Color
Alcohol Content
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Mash Temperatures
Mash temperatures are critical to
determining body, fermentability and
developing the aroma & flavor
profile.
Depending on the style of beer
brewed, type of malt and/or adjuncts
used, a different mash temperature
or a combination of temperatures
may be beneficial.
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Mash Temperatures
Phytase (Acid) Rest
• 86 - 126°
• Desired pH 5.0 – 5.5
• Acidifies the mash Works best with soft or
sulfate water, cannot overcome alkalinity
of strongly carbonate water
• Best with under modified malts, and has
very little reduction in highly kilned malts
• Will not reduce the pH a lot by itself, not
commonly used in modern day brewing
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Mash Temperatures
Phytase Rest
• Historically used with pale malt in
Plzen due to water devoid of
minerals, mash would not reach
proper pH level.
• Phytase breaks down phytin into
minerals and phytic acid, and
removes ion buffers, which lowers
the pH to the proper range.
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Mash Temperatures
Beta-glucanase Rest
•95-113°
•Optimum pH 4.5 – 5.0
•Beta-glucans are carbohydrates
found in the protein layer in grains
•Found in rye, wheat, oats and
under modified malts
•May cause haze unless properly
degraded
•Not needed for well modified
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Mash Temperatures
Beta-glucanse Rest
•Good for under modified malt, and
umalted barley, wheat, rye and oats at
≥25%.
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Mash Temperatures
Proteinase (Protein Rest)
•111-131°
•Optimal from 122°, with optimum pH
range 4.2 – 5.3
•Breaks down peptones, polypeptides
and peptides to make them smaller,
improving clarity without negatively
affecting head retention or body.
•Increases extract efficiency
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Mash Temperatures
Protease Rest
• Breaks down long-chain proteins
to medium-chain, and mediumchain to short chain.
• Under-modified malts contain
long-chain proteins – they are not
soluble and do not contribute
much to the beer except haze.
• Typically 15-30 minutes
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Mash Temperatures
Peptidase Rest
• 115-135°
• Optimum pH below 5.3
• Protease and Peptidase are
considered proteolytic enzymes, one
of two main classes of enzymes in
the mash
• Breaks down polypeptides and
peptides to amino acids (FAN)
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Mash Temperatures
Peptidase Rest
• Peptidase provides wort with amino
acids that will be used by the yeast.
• In fully modified malts has done its
work during malting process
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Mash Temperatures
Cytase Rest
•113 - 131°
•Optimum pH 5.5
•Dissolves protective cellulose
coating of barley grains, giving
access to the starch
•Good for under modified malt,
and umalted barley, wheat, rye and
oats at ≥25%.
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Mash Temperatures
Amylase• Any of various enzymes that cause starches
to break down into smaller sugars, especially
maltose, by hydrolysis. There are two types
of amylases, alpha-amylases and betaamylases. α-Amylase is a protein enzyme
that hydrolyses alpha bonds of large, alphalinked polysaccharides, such as starch and
glycogen, yielding glucose and maltose. It is
the major form of amylase found in humans
and other mammals. B-amylases are found
in bacteria, molds, yeasts, and the seeds of
plants. Free Powerpoint Templates
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Mash Temperatures
Beta-amylase Rest
• 131 - 150° is optimal, nearly completely
deactivated at 154°
• 153° works well as a compromise for
beta and alpha combined
• Optimum pH 5.0 – 5.6
• Creates small sugar chains that are highly
fermentable and leaves the lowest
finished gravity and lightest body
• One of the diastatic enzymes required
for saccharafication
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Mash Temperatures
Alpha-amylase Rest
•149-162°
•Optimum pH 5.3 – 5.8
•Produces glucose, maltose and
unfermentable dextrines
•Leaves the highest finished
gravity and fuller body
•Can be slower to work than ßamylase
•Most active at 158°
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Mash Techniques
• Single Infusion Mash
• Step Mash
• Decoction Mash
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Mash Techniques
• Although all mash techniques
require different processes, they
do share some for enzyme health:
– Grains must be properly crushed
– Grains must be mixed well with mash
water
– Temperatures must be consistent
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Single Infusion Mash
• Primarily targets alpha and/or betaamylase enzymes, most limiting of
mash techniques.
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Step Mash
• Allows a wider range of enzymes
to be targeted depending on beer
style and desire characteristics
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Decoction Mash
• Also allows a wider range of
enzymes, but can more limited
than a step mash depending on
how many decoctions are
performed.
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Exogenous Enzymes
Commercial enzymes exist that can
be added to your mash.
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Resources
• How To Brew – John Palmer
• New Brewing Lager Beer – Greg
Noonan
• Brewing – Michael Lewis & Tom
Young
• Brewing Better Beer – Gordon Strong
• Malt – John Mallett
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Summary
• Although fragile, enzymes are
reusable and generally affected by
temperature and pH
• Enzymes have an optimum
temperature and pH that they are
most active
• Enzymes have a significant effect on
the finished beer and is also present
in yeast cells
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Summary
• Understand the primary mash
enzymes and their optimal
temperature and pH levels
• Understand the factors that denature
enzymes
• Know what you want to accomplish
before deciding your mash technique
• Understand diastatic power
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Questions??
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