How Does A Keg Washing Machine Clean Kegs? Kegs are a brewer's best friend in many aspects, so it falls to us to make sure they stay in good condition and can handle the next batch of beer. Manually cleaning a keg is an exercise in time and patience, but keg washing machines make this process much less painful, especially in large brewing operations. We’ll provide you with an overview of how a keg washing machine cleans kegs so you can understand the most important parts.