I'm doing my first brew from a kit. I added the yeast to the wort (according to the instructions I have). In the first day or so, nothing happened. In the second and third days, the airlock was bubbling intensively. But after about three days, the bubbling stopped. Does this mean something's wrong with my yeast? or is it okay?


3 Answers 3


Assuming the temperature is steady around 68-72F, then it's probably fine. Often, the vigorous fermentation you saw does dramatically slow after 2-3 days. So relax, have a beer.

If the temperature dropped to the mid-to-low 60s, then it possibly stalled and you should try and slowly raise its temperature. Take it off the basement floor, or place it in a temperature-stable closet.

  • Thanks! low temperature is not a problem, but what if the ambient temperature is 77F? will it damage the process?
    – yoki
    Oct 20, 2016 at 12:04
  • 1
    1. Your beer is probably still fine. 2. Try and lower the temperature into an optimal ale range (68-72). 3. This high temperature might produce some off-flavors, but most of these off flavors can be reduced (or even eliminated) by letting the beer sit (condition) for awhile. Perhaps an additional week or two in the fermenter, then let the bottles carbonate and the flavors will mellow in time.
    – Sam
    Oct 20, 2016 at 12:15
  • its fine, just get an OG tester and you can monitor it - drops more and more slowly as time progresses. Just leave it alone for a week Oct 22, 2019 at 7:22

I'm sure that this has been mentioned hundreds of times on here and other web sites but I'll say it again... an air lock that isn't visibly bubbling isn't an indication that fermentation is over.

Let's take that sentence apart and look at some of the reasons why:

  • Fermentation may have slowed and you're not seeing a bubble during the time you're watching.
  • Stuck fermentation.
  • CO2 is escaping through another route (like around the bucket lid)
  • All three of these.

So, aside from not seeing active bubbling, how can you tell when fermentation is over? The generally accepted way is for your gravity reading to be the same for 3 days in a row (you would normally see this at or very near your predicted FG).

OK, so what do you do if you don't have a way to measure gravity? Let the fermenter sit there for a MINIMUM of 10 days. It won't spoil or go bad as long as the two enemies of beer (light and oxygen) aren't introduced. C02 is heavier than Oxygen, so part of the natural process is that Oxygen won't be introduced (don't slosh it around) and as long as you're fermenting in a dark room, light shouldn't be an issue (opening the door and looking won't hurt it).

  • 1
    I think it a slight exaggeration to say that "oxygen is the enemy of beer". Without oxygen beer might not be produced at all, as yeast needs oxygen to grow/multiply. Granted production of alcohol is basically anaerobic but even oxygenating wort in the later stages of brewing does not guarantee failure - far from it. I pour fermented beer onto the priming sugar in 25 or 50 ltr buckets and and then bottle it. I have done this for many years. The beer tastes fine. Oct 21, 2016 at 7:36
  • 1
    Most people syphon it over because they don't want their beer to taste like Heiniken. Oct 21, 2016 at 14:43
  • Has anyone told Heineken this? :0) Oct 22, 2016 at 12:45
  • I think that it's skunk when it's fresh by design. As my late uncle used to say, "I like cheap beer because it has taste. It tastes bad but at least it has taste." Oct 26, 2016 at 19:07

When i see my brew has stopped bubbling I remove some water from the airlock and it starts bubbling again. Not aggressive as before so figure the activity has slowed down.

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