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Enzymes & Mashing

Enzymes & Mashing

Amino acids may occur singly, in short chains known as peptides, or in longer chains as proteins.

A special class of proteins are called enzymes. Where most other proteins tend to have storage and structural roles, enzymes make things happen. Enzymes are catalysts, and as such, they promote chemical reactions without changing their own structure or character. Enzymes are generally given names that end with "-ase."

The complex protein of the raw barley kernel includes some enzymes, but others are developed during malting. The critical mashing enzyme known as alpha-amylase is an example of an enzyme that is absent in raw barley but gets formed during malting.

Beta-amylase works only from the end of the starch chain and "bites off" two sugars at a time.

Beta-amylase has optimal enzyme activity between 140° and 149° F

Beta-amylase denatures at 149 F in 40-60 minutes.

The alpha amylase enzyme isn't as selective as the beta. It can break apart starch chains at almost any point in the starch chain. As a result, it usually breaks long chains 100 to 500 sugars in length off of the starch molecule.

Alpha-amylase has optimal enzyme activity between 155° and 158° F

Alpha-amylase denatures at 153 F after two hours.

Table 5 - Major Enzyme Groups and Functions

 Enzyme

 Optimum Temp Range

 Optimum pH Range

 Function

 Phytase

 86 - 126°F

 4.4 - 5.5

 Lowers the Mash pH. No longer used.

 Beta Glucanase

 98 - 113°F

 4.5 - 5.0

 Best gum breaking rest.

 Peptidase

 115 - 135°F

 4.6 - 5.2

 Produces Free Amino Nitrogen (FAN).

 Protease

 115 - 135°F

 4.6 - 5.2

 Breaks up large proteins that form haze

 Beta Amylase

 130 - 150°F

 5.0 - 5.6

 Produces small, highly fermentable sugars.

 Alpha Amylase

 155 - 167°F

 5.3 - 5.8

 Produces larger, less fermentable sugars