The starch source may be used alone or with a secondary starch source.
Beer is composed mostly of water.
The starch in beer provides the fermented material and is a key determinant of the strength and flavor of the beer. The most common starch source used in beer is malted grain.
Grain is malted by soaking it in water and then drying the partially germinated grain in a kiln. Malting grain produces enzymes that convert starches in the grain into fermentable sugars Different roasting times and temperatures are used to produce different colors of malt from the same grain. Darker malts will produce darker beers.
The use of hops in beer was recorded by captive Jews in Babylon around 400 BC.
Hops contribute a bitterness that balances the sweetness of the malt, floral, citrus, and herbal aromas and flavors to beer. Hops also have an antibiotic effect, the acidity of hops is a preservative.
Yeast is the microorganism that is responsible for fermentation in beer. Yeast metabolizes the sugars extracted from grains, which produces alcohol and carbon dioxide, and thereby turns wort into beer. Yeast also influences the character and flavor.
