Can I use PBW cleaner on the Grainfather Brewing Units? You can use PBW to clean the Grainfather Brewing Units. Use the suggested dosage of 7 L (7.4 US qt) of water and stick with the recommended heating temperature of 55°C (131°F). Related articles What do I clean the Grainfather brewing and fermenting vessels? Is CIP (clean in place) possible on the G40? What is the green gunk/phlegm/algae coming from my counterflow wort chiller? I have noticed that my element has some burnt material on it – is this normal? Why does my GF30 has excess oils appearing after I've cleaned the unit, what should I do?