Anyone seen this before? Very light bread mold look only on the surface of primary fermentation. All equipment StarSan’d before use. I’ve been home brewing for many years and never had this happen so, no clue if this batch is ruined. Safe to drink? Also, brewed this 3 weeks ago.

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  • I read some comments elsewhere that it was safe to drink but, it smelled and tasted so bad I had to dump this batch. :( Still interested to hear any advice/comments. Obvious steps now are to thoroughly clean with chemicals before using again.
    – AtariPixel
    Jan 20, 2019 at 22:43
  • what was the taste ? acidic ? Sulfidic ? rancid ?
    – JeanMi
    Jan 21, 2019 at 8:22
  • I'm not sure how to describe it but, it smelled like bread mold. The sample I tasted was from the bottom and the taste was the same as the bread mold smell.
    – AtariPixel
    Jan 21, 2019 at 12:44
  • 2
    I'd guess some part of the process of getting the wort into the fermenter introduced the infection. When you're cleaning and sanitising, do an extra check on pumps and transfer hoses (etc.) for infections.
    – Kingsley
    Jan 21, 2019 at 22:10
  • I did eventually find the culprit after thorough investigation. The Mr. Beer spigot has a rubber piece inside, which I soak in cleaning solution before use every time. Turns out, there is more to this small rubber piece. You have to fold it inside out to get to every crevice. It's very difficult to do because you feel like it will break if you keep bending the rubber. After much struggling, I got it turned inside out and the mold inside almost made me sick. So, clean every surface and anything that can be turned inside out, do it :D
    – AtariPixel
    Dec 20, 2021 at 18:00

2 Answers 2


Seems like pieces of a pellicle from bacterial infection. Sanitize everything with bleach, rinse properly with water and then starsan.

  • I agree, bleach it all or replace it. The greenish blue color reminds me of a bread mold.
    – jsolarski
    Jan 21, 2019 at 16:17

I was once told that a general rule is any white infection is salvageable as a sour if you so choose, any green must be dumped. Personally I hate sours and will dump all infections, and that's definitely infected. Dump it, don't even bother tasting it

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