Beer: The Production History and Consumption Of Beer

Dan James

The first and most important step in brewing is cleanliness. "Brewing is ninety percent janitorial," said Frederick Bowman, founder of Portland Brewing. (Bowman) The first step in the actual brewing process is malting. Malting is what is done to the barley to prepare it for brewing. The steps of the malting process release the starches that are contained in the barley, while minimizing haze and off-flavors. Grain is allowed to soak in 60? F. water to increase the moisture content of the grain to about 40-45%. The grain is usually spread out on the floor of the germination room, or some other container. These grains are kept at a temperature of about 60? F. The germination is complete when the sprout has grown to about 3/4 the length of the grain and the hard part of the grain, or the shell, has turned soft. The goal for germination is for the starches within the grain to break down into shorter lengths. At this shorter length stage, the grain is called green malt. Kilning is the next stage after the grains have sprouted. Kilning is the process of drying the grain in the kiln where the temperature is slowly raised during the 30-35 hour period. After kilning, the result is finished malt, with soluble starches and developed enzymes. These grains each have a different and distinct flavor depending on how long they are cooked in the kiln. (Porter)

After the malting, the grain is ready for milling. Milling is the cracking, and crushing of the grain. This procedure is controlled carefully so as to break the grain while keeping the husk as large and as intact as possible. Milling allows the grain to absorb the water it will be mixed with later as the water will extract sugars from the malt. The malt will now be mixed with warm water in the mash tun. This vessel holds the grain and water mixture for a period of time. Two important things will take place in this step. One is to break down proteins to the more soluble and usable amino acids, providing food for the yeast and foam for a nice head on the beer. The second thing is to break down the starch to simple sugars so yeast can convert them to alcohol and carbon dioxide. (Porter)

Mash filtration consists of filtering the converted mash by gravity or pressure in a lauter tub or mash filter to separate the insoluble matter in the malt from the soluble sugars and nitrogen compounds. The sugar liquid recovered is called wort, pronounced wert, or sweet wort. Boiling the wort is best but is also the most expensive method, Microbreweries generally use this method. The sweet wort is boiled and treated with hops in the brew kettle in a planned schedule, usually somewhere between 30 and 90 minutes. The boiling has many effects: all bacteria are killed, it produces color and flavor compounds, the so-called browning compounds, from the malt and sugars. Boiling the wort extracts bitter and aromatic flavor compounds from the hops, and volatilizes most of the harsh hydrocarbons. It sterilizes the wort and stops all enzyme action. (Porter)

The boiled wort is strained to remove the hops and then transferred to a holding tank called the hot wort tank. The insoluble matter, called trub, is centrifugal separated in the whirl pool tank. The wort is now passed through a heat exchanger that rapidly cools the liquid. Cooling is necessary in order to add the yeast. Yeast is unable to ferment or grow at high temperatures, so cooling the wort to about 70?F is needed. Here is where hydrometer readings are taken to record the amount of sugar in the wort by measuring the density of the liquid. This is called the specific gravity. The specific gravity is used in determining the alcohol content of the finished beer. The more sugar there is, the more dense the liquid. The higher the specific gravity, the more sugars there are available for fermentation, producing more alcohol. (Porter)

It is here in the fermentation tank that the yeast changes the sugars into alcohol over a period of days or weeks, depending on the style of beer being brewed. Ferment is taken from the Latin "to boil". Watching the yeast in active fermentation, one can understand the reason the word is used. Fermentation begins with pitching,