I used Fermcap for the first time in my last brewday. I was using my trusty old system, with 6.5 gallons in a 7.5 gallon pot, so tried the Fermcap. Not only did I not get a boil over, I never got much foam at all! I used it according to the package directions- 2 drops per gallon, I believe.
But, yesterday, I forgot to add it to my starter in my Erlenmeyer flask. THAT boiled over on my stove.
For those of you who have used Fermcap with sucess, how much do you add to the boil? I don't need it for fermentation, as I never have blow-offs, but I HAVE managed to boil over a 5 gallon batch in a keggle. Indoors. What a mess! I'd like to be able to start with 12 gallons in the keggle and not have it all over my laundry room floor!
The first beer I used Fermcap on was kegged Monday, so I'll be able to start checking foam stability in a day or so.