• There are only four main ingredients in every kind of beer. The different styles and flavors in beer come from the proportions and types of the different ingredients used. Beer is made using essentially the same method and ingredients all around the world, whether home-made or produced in a commercial brewery.
  
  

Water

• More than 90 percent of beer is water. The regional characteristics of different beers are greatly influenced by the natural differences in the water between regions. Today, the traditional flavors associated with regional beers can be replicated by adjusting the chemical composition of the water used.
  
  

Grains

• One of the four main ingredients of beer is always some kind of cereal grain. The most commonly used grain is barley. The barley is malted by soaking it in water until it is partially germinated and high in starch. The barley is then commonly roasted, with the temperature and duration of the roasting process affecting the final flavor and color of the beer. Sometimes beer is made from wheat, corn or rice, in addition to, or instead of malted barley.
  
  

Hops

• Hops are the flowers of the hop vine. They are added to beer to impart bitterness and balance the sweetness of the malted barley. Hops also affect the aroma of the beer.
  
  

Yeast

• Brewing yeast is necessary in beer-making for fermentation. Yeast causes the sugars in the malted barley or other grains to ferment, producing alcohol and carbon dioxide. This gives beer its alcohol content and gives some beers a slight fizz. The yeast also affects the flavor of the beer. Different types of yeast are used to make ales and lagers.