I used to use it, but I stopped fro two reasons. First, I found I really don't need it. For starters, I make a qt. of wort in a 6 qt. pot, so no danger of boilovers. In the kettle, I spray the foam down if necessary. I use big enough fermenters that my blowoff is minimal, if any. Second, there is a slight possibility of negative health effects. Even though slight, I have enough health issues already to not make me want to chance any others.