With fermented pickles, you don’t add an acid directly to the vegetables. Instead, you let a specific kind of acid-producing bacteria—lactobacillus, in the case of sauerkraut—run wild. (View Highlight)
Lactobacillus bacteria are everywhere. They’re on our skin, in our bodies, and on the fruits and vegetables we buy and eat. They’re generally considered to be “friendly” bacteria, meaning they aren’t harmful to human health and may even be beneficial in some cases (View Highlight)
Lactobacillus has two important qualities: It can survive in oxygen-free environments, and it can tolerate salt better than many other microorganisms. It’s these two qualities that we exploit to successfully ferment vegetables, like cabbage in kraut (View Highlight)
While there isn’t full agreement among pickling experts about the perfect amount of salt for the fermentation of sauerkraut, the general rule of thumb is about 2% by weight (View Highlight)
The salt has an important second role: It draws moisture out of the cabbage’s cells through osmosis, forming a salty brine. Because the cabbage is shredded, its surface area is maximized, meaning that a surprising amount of brine can accumulate even from a juice-free vegetable like cabbage. With the help of some mechanical bruising through kneading and squeezing the cabbage, its cells break down even more, speeding up the release of liquid (View Highlight)
This brine brings us to the second important quality of lactobacillus—its ability to survive in oxygen-free environments. When we submerge the cabbage in its own brine, the lactobacillus and other microorganisms living on it are deprived of oxygen. Many will die as a result, but lactobacillus kicks into anaerobic (oxygen-free) fermentation mode, converting the cabbage’s sugars into lactic acid while creating by-products like carbon dioxide. You’ll know that fermentation is underway when your cabbage starts bubbling and burping (View Highlight)
The main enemy throughout is oxygen, which is why you want to keep your cabbage submerged in the brine the whole time. Sometimes molds can form on the surface of the brine, especially in the early stages, when the cabbage hasn’t fully acidified yet; mold on the surface isn’t ideal, but it’s not a sign that your kraut needs to go in the trash, either. Just carefully scrape it off and proceed as normal (View Highlight)
If you plan on making large batches of sauerkraut and other pickles, it’s worth investing in a real ceramic fermentation crock (View Highlight)
The kraut will keep for many months in the fridge at this point. If I’m being honest, I’ve kept some for more than a year. It eventually loses its sparkle and starts to taste dull and old (View Highlight)