There are many kinds of brewers, from extract brewers making their beer in five-gallon (19 L) buckets to commercial brewers making their beer in multi-story fermenters. The skills these brewers need and the procedures they use vary substantially. However, there are two skills that every brewer needs, no matter what size brewery they brew in: cleaning and sanitizing.

Cleaning and sanitizing your brewing equipment is the first step listed in the procedure on brew day. Your brewing equipment needs to be as clean and as free from biological growth as possible. The only organism you want growing in your fermenter is yeast. Growth of other organisms in unfermented beer (called wort) can spoil the resulting beer. Contaminated beer may turn out sour or develop other off flavors and aromas. In addition, the beer may overcarbonate and gush when opened. In extreme cases, your bottles may explode.