Lacto-fermentation is one of the safest methods of food preservation. You don’t need a starter culture. It requires no electricity, though once created lacto-fermented products are best refrigerated. When you have a surplus of a particular vegetable from your garden, lacto-fermentation is an easy way to make use of it, the result being a delicious, probiotic, healthy condiment. You can also ferment different vegetables together. The basic idea is to submerge veggies in brine (saltwater with your choice of herbs and spices), and let it sit at room temperature for some time (from a couple days to a few months) until it reaches the degree of fermentation you prefer.
Sauerkraut and kimchi are some of the better known vegetable ferments. Both of these are most often made in the fall, but can also be made in late spring. And you can ferment your summer vegetables, too. In our area, there’s still time to plant lots of these summer veggies, like cucumbers, summer squash, okra, and snap beans. Vegetables can be fermented whole, in slices, or in chunks. The size of pieces is up to you, as is the size of container. Last year I did a post about fermented green tomato “olives.”A few simple guidelines keep harmful microorganisms from growing in these ferments, and help beneficial microorganisms to grow there.
- Use raw veggies. They have microbes and enzymes that help the process get started. Cooking destroys the enzymes and kills the good microbes as well as the bad.
- Use salt. It is possible to ferment vegetables without salt, but much easier with salt. Salt kills many kinds of harmful microbes, but it lets lactobacilli and some other beneficial microbes grow. The amount of salt depends largely on your taste. Three tablespoons of salt per five pounds of veggies is one good ratio to try out. We use sea salt in our ferments.
- Non-chlorinated water is best. Chlorine kills good microbes along with bad ones. If your water is chlorinated – and especially if it’s heavily chlorinated – it’s a good idea to let it sit out overnight before using it in a vegetable ferment. Or, bring it to a boil and let it cool. Either of these methods will remove the chlorine from the water.
- Metal containers are not recommended. Glass, ceramic, and food-grade plastic are all fine.
- Keep the veggies submerged. A plate or a food-grade plastic bag full of water can be used to weigh the veggies down so they stay underwater.
- Keep flies out, while also letting gasses out. We do this by fastening a cloth tightly over the top of the container. Some people use airlocks – which let gasses out but not in – instead of cloth. Microbes respire, and completely airtight containers can build up too much pressure.
- The warmer the temperature, the faster the ferment. As it progresses, it gets stronger and more sour. Taste your ferments regularly to see if they’ve reached the stage you think you’ll like the most. Then, you can put them in the fridge to essentially stop the process. (It will still progress very slowly.)
- If anything visibly grows on the top, skim off what you can. You don’t have to get every last bit. If you push any veggies that made contact with it under the surface, that helps ensure that any microorganisms unable to tolerate saltwater will die. Some ferments, including fermented cucumber pickles, should be skimmed regularly.
- If it tastes bad, don’t eat it. If you’ve followed all the above guidelines, this should be very rare. I can’t recall a fermented vegetable that tasted bad, but if I had made one, I would throw it out. (I will note, however, that my appreciation of fermented vegetables has grown with time.) Our bodies know a lot about what is good for them.
Sandor Katz, author of Wild Fermentation and The Art of Fermentation, also created the Wild Fermentation website which includes a vegetable ferment support forum. If you have something you want to ferment and you’re looking for more information about how to do it, the Wild Fermentation forums are a great place to look. The same is true if you’re fermenting something and aren’t sure if it’s going fine or not.