Spoilage & Safety

Lacto-fermentation is an anaerobic process meaning that it requires an oxygen-free environment. If you are using a jar or open crock method for your fermentation, there is a chance that surface molds such as kham yeast, which is white, may develop.

DON’T PANIC ! When I find mold, I simply skim it off and transfer to a clean jar. Some cultures even allow a yeast to develop over a ferment as a natural lid.

I too tried this out and it worked!

Food born pathogens such as botulism cannot survive in acidic environments created by fermentation. The USFDA even considers it to be the safest method of food preservation and states that there are no documented cases of food borne illnesses attributed to this method. You’d be better off pickling a vegetable than eating it raw. If you are concerned about what you have created just let your nose be your guide. It it is really unfit to eat, you will smell it.

If you do have kahm yeast, catch it before it spreads too far and gives an off-flavor to the rest of your veggies.

Here is a picture of kahm yeast just starting! Quick, get a spoon and skim it out - or go the extra step and transfer the good veggies into a clean jar.

Sometimes there are bubbles you can see from the carbonization in the ferment.

Here is a pretty pink kahm yeast from a red-beet ferment!

Things to consider to prevent spoilage

• Vegetable Submersion - It is important to check regularly, particularly during the first few days as beneficial bacteria are proliferating and creating an acidic environment.

Sometimes vegetables will swell and rise out of the brine, if this happens press vegetables back under and add more brine as needed.

You can use a weight such as a smaller jar filled with water, a rock or a leaf to help you keep your veggies under brine.

Do not close the lid too tightly or it could result in a jar explosion.

• Salt Content - The purpose of salt in lacto-fermentation is to inhibit the growth of undesirable pathogens including molds and other microorganisms.

Too much salt will not allow lactic acid to occur fully but too little salt may result in off flavours, mushy vegetables or possibly mold.

The spectrum is from 2-4% salt depending on your vegetables and thickness.

• Introduction of a Starter Culture (i.e. backslopping) - The introduction of an already established starter culture can help establish an acidic environment immediately.

It will act as extra insurance that your ferment will work out. However, this skips some steps in bacterial succession that would otherwise occur so some people choose not to use starters for their vegetable ferments.

Have questions about your ferment? Add your pictures and questions here so the rest of the community can learn from your experiences!