How do I tell if this is Kahm yeast or something more sinister?

April 11, 2019 4:08 PM

I've a new fermentation crock that's been going 3 weeks now with beets, radishes, and turnips. I pulled it out to check and there's some growth on top. I've well familiar with Kahm yeast on pickles and other things I've fermented, but the color of the beets has dyed everything so I'm not sure what the growth is on top.

It's clumped together more than I would expect and some parts above the water look the whitish, but what's been in contact is a dark color. Normally if this were white I'd scrape it off and keep going no problem (I was targeting 4-5 weeks on this one). I'm hoping the answer isn't just throw it out there's no way to be sure, but if that's the case, that's the case.

posted by Carillon to Food & Drink (2 answers total)

Hmm. Can you post a picture? Normally if it's white I just scrape it off and keep going. Colorful mold is what I am more careful of. But if it looks fine and tastes fine...I have been known to just carefully get rid of everything that was above the liquid line and eat it anyway. Haven't died yet. YMMV, of course.

Make sure your airlock works, and maybe add a bit more salt next time. You peeled everything, right?

Fermenting stuff is awesome. If you haven't seen Li Ziqi on Youtube, check it out - she posts a lot of recipes for fermented veggies and even meat. It's Sichuan so there's a ton of preserved pepper ideas.
posted by ananci at 5:25 PM on April 11, 2019 [3 favorites]

You could culture some of it on neutral colored food/growth medium (ideally under the same conditions for everything except beet color) to see if it’s a kind of crud that is naturally some scary color, or if it makes little whitish yeast cakes.

That would take a while, but you could keep the batch fermenting and in a week or so have better evidence about what’s going on.
posted by SaltySalticid at 6:20 PM on April 11, 2019 [1 favorite]