A few years ago, as we started becoming "food nerds", we got introduced to fermented foods. Turns out there's more to "fermented" than wine and beer. As I recall, it started with a milk culture we began feeding our son. Called "piima", it is pretty much "milk snot" -- a stringy, gelatinous substance you get by mixing a starter with milk and leaving it on the counter overnight. Turns out it, or something very like it, is also pretty popular around here. We mixed it with various other substances to make a magic potion for the kid, and he loved it.
Our next step was lacto-fermentation, where the idea is that you preserve various foods by convincing some sort of bacterium to make lactic acid, which in turn preserves the food. That's where we get sauerkraut, but also chutney, mustard, ketchup, fish sauce, kvass, and about a billion other things. Modern variants of these foods typically aren't lacto-fermented (it's not one of Heinz's 57 flavors), but they all descend from fermented ancestors.
Homemade sauerkraut was, for us, a gateway drug. Far superior in both taste and nutritional value to the vinegar-soaked mash available in stores, when done well homemade sauerkraut aids digestion, increases the vitamin content of its ingredients, and will quickly teach you to refuse anything but the best. The recipe is simple: chop high-quality, firm cabbage in to small pieces, mix with about two tablespoons of salt per head, pound the bejeebers out of it with something hard, like a wooden spoon, so that it releases its juices, and pack it into quart jars. Add water if necessary to keep the cabbage below the level of the liquid, screw the lids down tight and leave them on the counter to bubble and hiss for a week as the fermentation gets going. When the hissing dies down, pack it away in the basement for a month or six -- it's harder to leave the second batch down very long, because you remember how good the first batch tasted -- and then dig in. No need to boil the bottles and seal everything, no need to keep it frozen or particularly cold; some folks I've heard of made some in a big bucket and left it in a relatively clean part of the garage for a year, after which they found it was still excellent. Purists wanting a larger batch without a crass plastic bucket can use a sauerkraut crock, a large ceramic pot where the cabbage is kept under the liquid with a plate weighed down with a brick, or some such. Somewhere I have a recipe I'm determined to try one day; it calls for a barrel and 55 heads of cabbage.
Similar techniques have worked very well for us to preserve string beans and jalapeno peppers, and quite a few other vegetables are certainly good candidates but we haven't tried them yet. When testing out a new idea, it's helpful to employ a decent sense of smell and healthy skepticism; if the sauerkraut juices are stringy and ropy, or the cabbage is particularly dark in color, or there's fuzz growing on it, I'd recommend tossing that particular batch. We tried salsa once but determined it had become alcoholic, most likely a function of how much juicier and softer tomatoes are compared to the other veggies we've tried. Use some caution until you've vetted a new recipe.
If you happen to have whey on hand, you can cut back on the salt. Whey of course comes from cheese making, but you can also get some by dumping yogurt (make sure it has live cultures, because you need those cultures in the whey) into cheesecloth and letting it drip for a while. The stuff that drips out is the whey, the stuff still in the cloth makes excellent cream cheese. For a quart of sauerkraut, replace a tablespoon of the salt with a tablespoon or two of whey. This will jump-start the fermentation. Grated carrots with a little fresh ginger is extremely tasty fermented this way. but won't last as long as sauerkraut, and should be refrigerated once opened.
In some future post, if I get around to it,