Gary Glass: Hi, I'm Gary Glass Director of American Homebrewers Association. Today I am going to explain how malt is used in all-grain brewing process. Brewing with malted grains involves three steps, mashing, lautering and sparging.
In the mashing process fresh grain is soaked in water at various temperatures activating enzymes in malt primarily to convert starches into fermentable sugars. Extractors skip this step, because extracts have already gone through the mashing process to produce fermentable sugars needed to make beer.
This chart from John Palmers How to Brew shows various malt enzymes and their associated mash temperatures. For most brews we are only concerned with the last two Beta and Alpha Amylase which breakdown starches to sugars.
Most mashers will use between one and two quarts of water for pound of grain, it will be kept somewhere between 140 and 158 degrees Fahrenheit for about an hour. The higher temperatures in that range produce more unfermentable dextrins that add body to beer.
Lautering is the process of removing a liquid wort from the grain solids. Most home brewers use a single vessel called the mash lauter tun to do this.
Sparging is the term used for rinsing the grain with conditional water to remove as much of the sugar as possible. The traditional method of sparging is called fly sparging, where water is added to the top of the mash tun as the mash tun is drained.
Some home brewers use an alternative form of sparging called batch sparging. For those new to all-grain brewing, batch sparging is one of the simplest methods you can use. In batch sparging all of the sparge water is added at once, stirred, re-circulated and then drained into the kettle.
Some brewers find batch sparging to be slightly less efficient at extracting sugars, but batch sparging requires less equipment and is faster and easier to perform than fly sparging.
So those are the basics of how malt is used in the all-grain brewing process.