Enzymes
The objective is to create a mixture where the yeast can get to sugars to convert them into alcohol.
The starches in grains like corn and wheat must be broken down with an enzyme in order for fermentation to take place. These starches need an enzyme to first break down the molecular chain that binds the starches together. Broken down it becomes a simple sugar. Once broken the yeast cells can eat these singular sugars and produce alcohol. The most common enzyme is barley that has been malted.
Malt Barley
Barley is just another grain, but malted barley is different. Malted barley has already started to germinate. At that stage the barley turns mostly to enzymes. These enzymes at on the grain to separate the chained linked sugars from the pulp. The germinated barley is only allowed to germinate a little bit, then it is killed by excessive heat from an oven at a certain temperature. This is done such that the enzymes still remain and can be activated with some heated water. These enzymes work on the sugars in the barley first, then they go work on the activate sugars in other grains present. Other than their own activation, they can activate sugars in other mixed grain at about 4 times the amount that they weigh. So 20% of the mash should be malted barley.
Sugar
Even if you use just sugar alone as an ingredient you still must heat it to break down the cellulose pulp to make the sugars yeast-friendly.
Amylase
Commercial alylase is available to convert chained sugar molecules to single molecules.
Two types: Alpha amylase and Beta amylase.
Alpha amylase is the heavy worker amylase thate breaks down the long chained sugar molecules to smaller parts. This can be found in powdered form.
Beta amylase breaks off the ends of these smaller chained sugar molecules into 1, 2 and 3 molecule sugars, the size the yeast cells can eat. Beta amylase mostly produces 2 chained sugars called maltose. Beta operates at temperatures between 126F and 144F, but can survive for short periods at 150F. Beta amylase is found in malted barley but cannot exist in a powder. There is a substitute powder that works the same way; Gluco Amylase Enzyme (Amyloglucosidase, AKA Gamma Amylase)
Gluco amylase breaks down the chained sugars into single molecule sugars that is easy for the yeast to eat. With Beta amylase there are small chained sugars that are not broken down and hence give the liquid body which is desired in brewing. Gluco amylase works at lower temperatures breaking down the smaller chained molecules produced by Alpha amylase to single sugar molecules so as to make the yeast is able to produce the highest alcohol content, the desire in distilling. Gluco amylase works slowly so it is introduced at the same time when the yeast in introduced.
