Malt

Barley is the major malted grain selected for use in brewing because of high levels of starch, low levels of protein and active enzymes after malting. Components include carbohydrates, nitrogen compounds and lipids.

Starch is the major carbohydrate. Limited amounts of simple sugars are already present in malt as a result of malting reactions. 10% of the grain may be cell wall materials such as cellulose, pentosans and b glucans. 20% of these are soluble and may be extracted into the wort and precipitate later when temperatures are lower. Malt nitrogen compounds include proteins, enzymes and nucleic acids.