How to Use Enzymes to Convert Starch to Fermentable Sugars
From the Yahoo Alcohol Fuel Group
Weigh your grain and make record of dry weight.
The ratio of each enzyme to weight of grain is 2 pounds per dry ton of grain.
The ideal amount of water for conversion: Enough to keep the grain under a few inches of water.
Before heating the grain/water mixture you need to test and adjust the pH of the mixture.
The enzymes become inactive below a pH of 4.5 or above 7.0 so adjusting the pH to between 5.5 and 6.0 will provide the ideal conditions.
If the initial reading is to low you can add calcium carbonate or bicarbonate of soda or if your pH is to high you can adjust with sulfuric or citric acid.
When your pH is in the working range you should begin cooking your grain until it begins to get soft. Then check the temperature and cool to 166F but not less than 132F.
Stir in Alpha amylase and let sit for 60 minutes, this will help to liquefy the mash a little and make it easier to stir.
After the Alpha amylase stage you may have to adjust the Ph of the mixture because Gluco Amylase is active between a pH of 2.8 and 5.0 so an ideal pH would be about 4.0.
Next stir in the measured amount of Gluco Amylase.
Gluco Amylase is destroyed by temperatures above 167F but the optimum temperature for final conversion is between 140F and 130F but do not heat or cool the mash after adding the Gluco Amylase.
Before adding your yeast you may need to add enough water to bring the Specific gravity down to 1.060, a little lower is ok but if it is higher then your yeast will die out before it gets all the sugars used up.
Let it cool naturally and you can add the yeast only after the temperature has dropped below 100F. These enzymes only convert starch and their related cellulose to sugar, they do not take the place of brewers yeast, and Yeast will still have to be added after sugar conversion.