Carboy fermenting time? (Seemingly long ferment)

Hi All,

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"?

Thanks!


**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.

I made (2) ThreBrewhouse IPA with included pack is in my secondary now...

Primary for 22 days, now secondary for 11 days and dry hopped with 1oz williamette... the airlock is still bubling. Fermentation is totally done, it is just off gassing no worries. Bottle in another week or 2...

8 days in primary is really short though... go for at least 2 weeks...

p.s. the one before that i left in primary for one months, and secondary for one month and it was still bubbling when i bottled it

Your beer is done fermenting. The airlock is bubbling because of changes in air temperature. The airlock can also bubble when barometric pressure changes occur. It doesn't mean it's fermenting- it just means that the co2 comes out of solution at higher temperatures. If you move it, it'll also bubble a bit.

If you added water to your beer, you may have diluted it a bit. I don't add water to my beer after fermentation has started. If you thought it was too strong, and needed to be watered down, that's one thing, but just adding water to a finished beer just waters it down.

You said your FG is 1.010- that's a good FG. You should still have some malt flavor. I shoot for a FG in 1.010-1.014 in most of my pale ales and blonde ales.

Thanks guys. I'll bottle in a week or so and leave it at that.

@YooperBrew: Actually, I didn't add any water after fermentation started. I only added the water the kit called for when I mixed it up. What actually happened is I lost some volume because my carboy was only 5 gallons instead of 6.