Lacto-fermentation is incredibly easy and safe! The only thing you have to worry about is making sure the veggies are submerged in the brine and that the brine is at least 2% salinity (so at least 2g salt for every 100g of water + veggie). Oh, and a way to let air escape while keeping bugs out (there are fancy water lock fermentation lids, but I just secure a dishcloth over the jar with an elastic). The jar should be clean, but doesn’t need to be sterilized. Let it sit somewhere that’s at least room temperature. Bubbles at around 24-48 hours mean it’s working! It’s safe to eat whenever, so let it sit for as long as you like and when it tastes good, put it in the fridge to slow the fermentation. I usually let mine sit for 1 to 2 weeks.
This should work with most veggies, since they’ll have lactic acid bacteria on their skins. I’ve never tried mushrooms, but I can’t see why they wouldn’t work.
