The primary ingredient used in traditional beer is malted barley, although other grains like wheat, corn, and rye can also be used. The malting process involves soaking the barley in water, allowing it to germinate, and then drying it to halt germination. This malt contributes sugars necessary for fermentation, which is carried out by yeast, resulting in alcohol production. Hops are another vital ingredient, adding bitterness and aroma to balance the sweetness of the malt. The combination of grains, hops, yeast, and water creates a wide variety of beer styles, from lagers to ales.