Hi guys it's my third brew I have done. I'm a bit worried about an infection. My brew is at day 7 and there is a lot of foam on the surface, also it doesn't smell like my first one( which was a success). My second brew I poured out for the same reason. Is this change in foam and smell because of a change in beer type. Or two infections in a row.

I clean my fermenter and utensils extremely thoroughly. All I can think of would be the kettle I use to fill it with. Any help please.

  • 2
    What sort of brew? What style of beer? What's the original gravity? What tempearature are you fermenting at? What yeast are you using? Did you make a yeast starter? What does the "foam" look like; can you take a picture? What does the beer smell like? Have you tasted it? What does it taste like? In what way has the foam "changed" from the last batch?
    – jsled
    Feb 20, 2016 at 4:32
  • I'm surprised that you mention the kettle as a possible source of contamination. Are you using a tea kettle or something similar to heat water to bring up your volume at the end?
    – BBS
    Feb 9, 2017 at 21:08

2 Answers 2


It sounds like krausen to me. Search images of "krausen" on the internet or have a look at this video: https://www.youtube.com/watch?v=VJ-M4ZFw5Fs


I would imagine, given the fact that you state you have cleaned everything thoroughly, this is what's referred to as "Krausen" or "Beer Head" and is perfectly normal and is most certainly NOT an indicator of an infection.

As stated on Wiki: Beer head (also head or collar),[1] is the frothy foam on top of beer which is produced by bubbles of gas, typically carbon dioxide, rising to the surface. The elements that produce the head are wort protein, yeast and hop residue. The carbon dioxide that forms the bubbles in the head is produced during fermentation. The carbonation can occur before or after bottling the beer. If the beer continues fermenting in the bottle, then it naturally carbonates and the head is formed upon opening and/or pouring the beer. If the beer is pasteurized or filtered then the beer must be force carbonated using pressurized gas.

The density and longevity of the head will be determined by the type of malt and adjunct from which the beer was fermented. Different mash schedules and cereal sources influence head retention. In general, wheat tends to produce larger and longer-lasting heads than barley.

In other words - don't worry about it! :-)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.