I've been using Fermcap-S in starters and fermentation for a couple of years. I pitched Nottingham yeast into an 1.063 IPA Tuesday and after about 8 hours it was going strong. Went in this morning to take a look and the air lock had blown off. Luckily, not a big mess in the fermentation fridge. This was 5.25 gallons in a 6.5 gallon Bigmouth Bubbler and, yes, I did remember to add 11 drops of Fermcap-S when transferring to the fermenter. I'm thinking the Fermcap-S must be too old. There has been more krausen on the last few batches and now this blow off. The bottle doesn't have any date on it, but I'm pitching it and picking up more tomorrow. Has anyone had a similar experience?