First off, I'm not worried or anything...this is purely an information gathering question. I brewed an AG kit (Brew House with the included Coopers yeast), started May 7. I racked it on the 15th after a few days of reasonably stable SG readings. OG: 1.042, Not-so-FG: 1.010. A bit high, but I thought it would finish itself off in the carboy without incident, and if it didn't go any lower then it was still okay.
There have been occasional tiny bubbles still rising, so I knew it was still fermenting. Today I noticed there are bubbles rising up into the airlock**. The ambient temp is 14, but yesterday the outside temp climed to 32C, so the basement may have climed enough to jumpstart the yeast.
I'm just going to leave it for a few days after the bubbles have ceased, maybe a week or so, but I'm wondering how long this fermentation might go on for. Does anyone have a rough guess beyond "until the yeast goes dormant, runs out of sugars to convert, or all dies"?
**Why are there bubbles in the airlock? Because my 6 gallon carboy doesn't seem to be 6 gallons. It seems to be 5, but I didn't notice that when I bought the used kit off Craigslist. I lost some beer when I racked and filled the carboy up to about an inch or so below the airlock stopper. That's why there are bubbles way up in my airlock. On the plus side, I figured having little headspace in the carboy would be a good thing.