MaltBut lets begin at the beginning. Every beer begins with barley grain. Each grain is a seed and contains all the chemical properties to sprout into a full barley plant under the right conditions. It is the maltsters job to manipulate this potential into a usable product for the brewer.
The process of malting barley involves tricking each grain into believing that it is time to sprout. This is easily done with a little warm water. The sprouting process activates enzymes in the grain that will later be used by the brewer in the mash. As soon as the barley begins to sprout the maltster quickly but gently dries it completely in a kiln putting the enzymes in suspension. The sprouts are removed and the remaining grains are sent on to the brewer.
MashWhen the malted barley reaches the brewer it is full of naturally occurring starches and the enzymes activated during the malting process. The brewer then takes the grains and adds them to a bath of warm water, typically between 148 and 158 degrees Fahrenheit. This is called a mash. It is at these temperatures that the enzymes are reactivated. A chemical reaction begins whereby the enzymes attack and break down the starches in the barley to simpler sugars. These sugars are the goal of the mash.
This is all done in a special brewers container called a lauter tun. The lauter tun is designed to contain the mash without leaking while being able to gently filter away the water through its bottom when the mashing process is complete. Lauter tuns are often insulated or use some other method to maintain a constant temperature mash.