How is ordinary barley (or other grains) turned into malt and why is it necessary?

The primary ingredient in beer is a malted grain, most often barley.

(For the sake of brevity, only barley will be discussed here but the variation between grains is minimal at best.)

Not only does the malted barley provide the sugars for fermentation, but also supplies enzymes for necessary to convert these sugars. Grains are simply the seeds of the plants and this is where the bulk of the sugars are stored.

The first phase of malting soaks the grains in warm water, triggering the seeds to germinate. This phenomenon occurs as the seed seeks to convert its starch reserves into a readily available food source for growth. Enzymes are produced within the grain and conversion begins.

The degree of modification - the term used for measuring conversion - is extremely important. The ideal condition allows the plant to convert as much starch into sugars as possible but does not allow the seed to use these sugars for itself.

As the seed begins to develop, a sprout (the acropsire) will begin to emerge from the grain. This is a sign that the development of the grain has begun to consume some of the sugars for growth. In order to inhibit further growth, the water is removed by drying in a kiln.

Drying must be done slowly and evenly. High heat will destroy some of the enzymes that the brewer will take advantage of in the mashing phase, where the sugars will undergo further conversion.

Then, the acropsire and rootlets are removed by tumbling and the malt is ready to be used for brewing.

Malt may be roasted or modified for various properties. The roasted malts are gauged on the Lovibond scale, which ranges from one to 600. For comparison, a typical American light beer may be produced from malt of less than five Lovibond, while extremely dark beers may contain malts of a few hundred Lovibond.

The finished malt is then shipped to the brewer where it will spend its time patiently waiting in a silo until its brewday arrives.

Milling the malt begins the brewing process. Water is sprayed over a filtration bed formed by husks, extracting the sugars and enzymes. At this point malt has served its purpose and the yeast will take over from here, turning those sugars into alcohol and carbon dioxide.

Chris Straub is a senior majoring chemical engineering and a Collegian columnist. He is also the great-great grandson of Straub beer's founder. His e-mail is cts150@psu.edu.