I had the mother of all blowouts a few batches ago and decided to try some FermCap-S.
I've now done 3 batches using the FermCap but it doesn't seem to be preventing blowouts at all. I'm an extract brewer so I normally do 3-3.5 Gallon boils for a 5 gallon batch. I put 10 drops in right before the boil when I add the extract.
It does help preventing boil overs. My understanding was that if you add it when you boil you wont have to add it when you rack. Am I off a wee bit? Do you have to add if for both?
Cause I see no difference in blowouts.