Enzymes Flashcards
What are the two enzymes critical for brewing?
α-amylase and β-amylase
What does α-amylase activity express as?
Dextrinising units (DU)
What process affects the levels of α- and β-amylase?
Malting process
What is the function of α-amylase?
Catalyses the random hydrolysis of starch to produce shorter glucose chains and sugars
How is α-amylase activity measured?
By timing how long it takes a solution of the enzymes from malt to break down a starch solution in the presence of excess β-amylase
What is the adequate range of DUs for malt used in an all-malt mash?
30-50 DU
What is diastatic power (DP)?
The capacity of the enzymes in the malt to break down starch
What combination of enzymes does DP represent?
α-amylase and β-amylase
How is diastatic power measured?
By estimating the amount of reducing sugars produced from starch breakdown through titration
What are the units of diastatic power?
- Degrees Windisch Kolbach (˚WK) (EBC) * Degrees Lintner (˚L) (ASBC) * Degrees IoB (IoB)
What are typical DP values for standard ale malts?
35-40 ˚L
What are typical DP values for pale malts?
100-125 ˚L
What are typical DP values for some six-row malts?
> 160 ˚L
How do ˚WK and ˚L relate to each other?
DP ˚Lintner = (˚WK + 16) / 3.5; ˚WK = (3.5 x ˚L) - 16
What is saccharification time?
The time taken to convert all of the starch in a standard mash
What is a typical range for saccharification time?
5-10 min or 10-15 min
What does a saccharification time longer than 15 minutes suggest?
A problem
