Fermentation Run Amok
This is a sort of thread redirect from the last few posts of the 'Newbie seeks feedback' thread.
I mentioned that after pitching the second batch of yeast, I had a thick 6" layer of foam in the carboy. Well, I came upstairs to get some work done and forgot about it. Couple hours later I go down to check on it and see a haze floating in the air around the carboy, in its large cardboard box/house. Then I notice the level of liquid is WAY down and the foam is up to the top and filling up the fermenter lock. I hear intermittent sounds of gas escaping under pressure.
I think, hey maybe I should clean out the lock, not realizing it's full of gunk. It comes off after some wiggling and WHUMP, it blows my hand up enough to hit the bottom of the counter, followed by a very thick ,heavy foam (with a strong alcohol flavor) rolling out of the bottle. Sounded like a very large champagne bottle opening.
After getting everything cleaned up and fitting a run-off hose to the fermenter, I went to clean the lock out and it's not full of foam at all, but a solid light brown cheesy substance which I'm assuming is yeast?
After the pressure was relieved, the beer level returned to normal, but how much of my pitched yeast was in that foam and cheesy stuff that blew out of the fermenter? Do I now, again, run the risk of not having enough yeast to do the job? Foam is still slowly pumping out of the carboy into a catch vessel.
Also, from seeing that blowoff, I'm assuming it is possible for a carboy to explode from fermentation pressure, but how often does that happen, or does the fermentation lock let go first, preventing that from happening?