fermentation fail - moldy radishes

Fermentation Fail – Moldy Radishes!

Fermentation Fail

Every fermenter will at some point experience a fermentation fail. This may be from an abundance of kahm yeast producing off smells, improper submerging of vegetables resulting in a layer of molded solids, or sometimes more mysteriously, a layer of mold that forms on the surface of the brine. It’s sad, but it does happen.

A few weeks ago I was gifted with a lot of radishes and baby carrots. The bagged kind, left over from a charity event I help out with. It’s no secret that I’ll use up produce no one else wants.

I put up a gallon and a half of radishes in brine. The gallon jar also included a bunch of baby carrots that were left over. The half gallon was in two quart jars, and when I checked on them a week or so in, one of the quart jars had a pretty beautiful layer of mold spreading across the surface of the brine.

fermentation fail - moldy radishes

Two large islands of mold, and a few smaller bits of what I think was kahm yeast.


fermentation fail - moldy radishes

Another shot of the mold islands.

Diagnosing a Fermentation Fail

So what went wrong here? There are a lot of options, but when I opened the lid, I noticed a gnat flying around. I didn’t specifically see the gnat fly out of the jar, but flies and gnats contacting the brine will pretty much always drop off some mold spores with them. I was using a white plastic lid on the Mason jar, and they notoriously seal poorly, possibly allowing a tiny flying bug in to contaminate the batch.

Dealing with a Fermentation Fail

A lot of people are absolute purists when it comes to mold on a ferment and toss the whole thing. I have a less stringent approach, and in this case was going to set it aside and see if the mold returned. I scooped everything out, agitated the surface to submerge any too-small-to-see action, and closed it back up. The next day, I realized that the activity had shifted the weight in the jar and that several radishes were floating. I washed my hands, reached in to grab the weight, which shifted further and fell to the bottom of the jar. Apparently these radishes really aspired to be compost, and in the end, I gave in to their wishes.

Had setting them aside gone better, I would have monitored for a return of the mold. If it came back, I wouldn’t have eaten it. If it didn’t come back, I probably would have.

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Stacie is a freelance writer living in Atlanta. She’s been fermenting for most of a decade, and is an enthusiastic maker of beer, wine, kraut, tempeh, and natto, as well as an avid keeper of bees. And dogs and cats.