When is it done?

[Mercenary]

So when does fermentation stop? My stout is still bubbling (once every 20 seconds or so) after almost three weeks of fermentation.

I want to move on to my next brew (an APA), but have to wait because I've only got two fermenters (and just one lid with a hole in it for the airlock).

So...when is it done?

[danno]

do you have a hydrometer? you're done when you get the same reading three days in a row. (and, you should also be close to your target gravity...)

[Fir Na Tine]

Has the krausen fallen?

I'd say you could move it to a secondary fermenter to free up your primary. The bubbling is most likely Co2 coming out of solution.

Do Danno said, take 3 consecutive hydrometer readings over a period of 3-4 days. If they're all the same, it's probably done and ready to bottle. Make sure it's at or near the recipe's final gravity prediction.

[redelephntlabel]

I've actually got a similar issue. I'm a first-time brewer and this is my first time on this site. I've got 5 gallons of what I intended to be a stout fermenting in a bucket with an airlock. After about three days, and no airlock activity, I cracked it open to take a look and there was krausen, so I figured I was okay, and just had a faulty seal on the airlock. So how do I know when it's done? I pitched two packets of Safbrew S-33 dried yeast and the krausen has well come and gone after only a week.

[redelephntlabel]

I also don't have a hydrometer.

[Mad Scientist]

I'd let it go another week, then bottle....if you are doing primary fermenter only (as opposed to use a secondary fermenter), you'll need that much time to let everything settle out. It iwll continue bubbleing, though it may slow down a bit.

Get a hydrometer with you next batch. They are not expensive.

Welcome by the way.