Amylase enzyme is a naturally occurring enzyme that is used to aid in the conversion of starches to sugars in the all grain brewing process. It is especially helpful in lighter beers with delicate malt character. This enzyme will begin to denature at temperatures above 149 F (65 C). At temperatures around 158 F (70C), the enzyme will denature after about 60 minutes. When the temperature reaches 194 F (90 C), the enzyme will denature in 5-10 minutes. Obviously, it is very important that the mash temperature not go above 158 F (70 C) if amylase enzyme is used.