My house was cool so I put a heat belt on a carboy of Merlot as I wanted to get a bit more fermentation out of it and I left it for about three days. I went to look at it and the heat must have caused the wine to expand as it went up into the air lock. I emptied the air lock and put some more water into it and once I took the heat belt off it contracted to where it is supposed to be in the carboy and now it's all fine. I had a minimum of head space in the carboy before the wine tried to escape out of the air lock so maybe that was a mistake.
Has this happened to anyone else?
Has this happened to anyone else?