Is anyone aware of some solid reference information on lacto-fermented vegetables? I am especially interested technical information, such as what off flavors may occur due to which circumstances.

The internet seems to be flooded with misinformation on the subject because of the probiotic fad and the air-lock vs open fermentation argument. These articles seem to gloss over the fact that spontaneous fermentation is unpredictable and that this has been done for ages in every fashion imaginable. I am trying to find some good information on how lacto fermentation can go wrong (or right) and why.

In the beer community, it is well accepted that fermentation temp and microbial strain affect the flavors in the final product. Home brewing documentation offers advice such as (this is very approximate):

  • Bubble gum flavors
    • Belgian yeast fermented in excess of X degrees Fahrenheit will exhibit such flavors.
  • Buttery flavors
    • Attributed to diacetyl, a compound produced by poor temperature control or a pediococcus infection.

In my specific case, I have a batch of fermented cucumbers that have a bit of a band-aid flavor to them (an off flavor also found in beer). I know now that they were fermented at entirely too high a temperature. I have also been consuming them safely for over a week now, so it's more a matter a taste than safely.

  • How much organic chemistry-speak do you want in your answer? Mar 7, 2015 at 18:17
  • Ever explored metacyc.org ? If not, it's a database of enzymes, reactions and metabolic pathways. It does help to know which organisms you have...but you can do a little educated-guess-work, since many families of organisms have similar behavioral "trends". Mar 7, 2015 at 18:25
  • I'm an CS&E guy so I can hang technically to a point, tho chem is not my field of specialty. Edit: I checked that website. That is probably beyond my chemistry knowledge.
    – Derpy
    Mar 8, 2015 at 0:19

1 Answer 1


You need the bible of lacto-fermentation 'the Art of Fermentation' by Sandor Katz.

That aside, the general rule is: if it smells and tastes appetizing then it's fine. If it has green, blue or black 'mold' on it, chuck it out. White is alright. Botulism is actually very rare with fermented vegetables. Fermenting is very safe compared to other preservation methods.

Sometimes I get a yukky whiff at the moment I open a fermenting crock, but then once I put a forkful on a plate for a minute it is fine and yummy. So don't decide in the first few seconds.

The best advice I can give on what are the prime factors for lacto going right (tasty healthy) rather than wrong (slimy inedible waste of food) is: use organic veg so you know the right bacteria is present from the start (or add a coupla organic cabbage leaves, they are foolproof). Also get your salt ratio right in the brine, it kills off the baddies. Consider the texture of your veg. If you are cutting/grating it finely, it will likely ferment hard and fast (the bacteria finds lots of surface area). Ferment theses for a shorter time than chunky or fibrous veg to get good complex flavours. Last tip- invest in a good crock with an airlock 'moat' on it and weights in it. they are pricey but really improve your strike rate a lot.

On flavour: veg that has been fermented 'right' has an unmistakable pickles tang at the start, then a lingering complex savoury musty ending. No matter what veg you use.

Oh, and cucumbers (gherkins) are widely held to be tricky to perfect, especially hard to keep crunchy. Beginners usually steer clear. Good first experiments are carrots, cabbages and cauliflower.

  • I'll look into the lacto bible you mentioned. The hurdle my brain is still stuck on is that with wild beer, there are styles where 'Musty Horseblankety Barnyard Funk' is considered a desireable flavor. Some people might call that an off flavor. That info is really hard to find for lacto veg.
    – Derpy
    Mar 8, 2015 at 0:28
  • Kratz's book is great, good reccomendation. But I have two of the "moat" pickling pots. I am now reluctant to use them. The "moat" lip makes them physically difficult to work with (getting hands inside etc.), and the "moat" water is always drying up (or getting dead insects in it). It's also difficult to see inside. I wish they made the moat such that it was outside the circumference of the crock, rather than inside it.
    – Kingsley
    Jun 1, 2020 at 22:29

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