Alpha-amylase (AA) enzyme is a bacterial-derived enzyme, dried. into a powder that breaks down starch into dextrins and simple sugars during mashing.
It's critical to have alpha-amylase enzyme present either from something like distillers malt or some other base malt to convert raw grains down to fermentable sugar. Use alpha-amylase enzyme as an additive during cereal mashing (to help get from gelatinization to liquefaction) to aid in the conversion of starch to sugar.