PBW (Powdered Brewery Wash) is a popular buffered alkaline detergent used in commercial breweries. Only 1 to 2 ounces per gallon are needed for cleaning fermentors, kegs, tanks, and most other equipment. You may soak your equipment in the solution overnight to avoid having to scrub off your mess. PBW is an environmentally friendly, biodegradable product that will not damage rubber, metal, septic systems, or your skin. PBW is an excellent choice as a soak cleaner because it does not require excessive heat as do most caustic based cleaners.