My beer iam fermenting which is now 7 days old has started producing a small amount of foam/bubbles on the surface! Everything else is spot on, just wondering if this is normal so near bottling stage? Please help

Follow up info: Starting gravity was 1.032. Temp has always been at 22 Celsius and the gravity is at 1.006 for second day now. No activity like yesterday as in small bubbles rising 2 surface.

  • Has the ambient temperature risen? If the beer warms up, CO2 can begin to come out of solution in the form of bubbles.
    – bughunter
    Mar 5, 2015 at 13:02
  • Yesterday was 22.7 and todays is 22.2. Nothing major Mar 5, 2015 at 13:05
  • 1
    Is this the first time you've seen foam on the beer? Usually you get a lot of foam (called krausen) after 24-36 hours, which then dissipates over the course of the next week or so. If you're seeing foam for the first time after 7 days, then it's likely the yeast was very weak and took a week to get going, or the yeast failed and the bubbles are due to an infection of wild yeast or bacteria. Mar 5, 2015 at 23:56
  • There was a foam for the first day or 2. I've checked today and it's still there! Is this ok??👌 Mar 6, 2015 at 8:08
  • Ok thank you. Temp is still ok at 22 Celsius and measuring at 1.006 for second day now. No activity like yesterday as in small bubbles rising 2 surface. Might place it in barrel tomorrow? Mar 6, 2015 at 18:40

2 Answers 2


Foam is not normal near bottling time, it usually means that fermentation is still happening - that is, it is not bottling time.

A few bubbles can be formed just from loss of CO2 (from a rise in temperature for example), but the best way to be sure is measure the specific gravity. See this thread.

Especially note, as the above thread points out, it's good to be patient.


This is when your fermentation is working and the "krausen" is your yeast cake on the top of the fermenting wort. This should make you very happy, your yeast is working and it is producing alcohol/beer!

See also, information on counting yeast cells to see how active your yeast is under a microscope.

There are also studies on under/over pitched yeast which I prefer just the right amount so as not to strain the yeast by under pitching or lose body by over pitching (may also cause a bitter beer taste).


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