Five Star PBW (Powdered Brewery Wash) is a patented alkali cleaner originally developed for Coors. PBW is designed to act as a soak or manual cleaner. Simply let dirty items soak overnight in PBW solution. After rinsing the next morning they will be shiny and clean. Never Scrub Again! PBW can effectively clean items that can't be reached with a brush or sponge, and is strong enough to remove impossibly thick, difficult, baked on soils. PBW is environmentally friendly, biodegradable, and will not harm the 'friendly' bacteria in your septic system.