Originally Posted by samc
I don't use anti foam, but read this
as it will correct a lot of the mis information about the stuff.
Great find there...
Still 15 gallons into a 15.5 gallon keg is mighty tight. I would put about 11-12 gallons into it, and use another vessel for the rest. Such as a 1/6 bbl sanke keg. Or just reduce your batch size by a gallon, or two, and give yourself enough headspace to not need to worry.