Saturday, January 30, 2010
Drink of Angels
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 maltster’s 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.
When 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 brewer’s 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.
Once the brewer decides that most of the starches have been converted, which usually takes an hour or so, the temperature of the mash is raised to around 165 to 170 degrees Fahrenheit to halt the enzymatic process. Then the water is drained away and collected leaving behind a bed of grain. More warm water is sprinkled or sparged on to the grain bed at about 165 to 168 degrees Fahrenheit. This rinses more sugars from the grains. The water is then drained and collected with the original water from the mash. This water with sugars, unmodified starches and proteins dissolved or suspended in it is called wort.
The wort is then boiled. Boiling the wort improves the beer in a number of ways. It kills any enzymes remaining from the mash that could later make the beer unstable. It sterilizes the wort reducing the chances of contamination. It reduces the amount of water which increases the concentration of fermentable and unfermentable material extracted from the grain. The fermentable sugars will be converted to alcohol during fermentation and the unfermentable sugars and proteins will contribute to the final beer’s color, head, aroma, mouthfeel, and flavor.
Hops are generally added during the boil which extracts the resins and oils. Hops added early during the boil contribute a bitter flavor to the beer which is valuable because they add a balance to sweetness from the unfermentable sugars. Hops added to some beers during the final minutes of the boil contribute aromas and very little bitter flavor to the beer.