Sauerkraut is a cabbage ferment commonly associated with Eastern European countries, but it’s likely that it’s history goes further back than that. There are tales of strips of cabbage fermented in rice wine feeding Great Wall laborers in China a couple of millennia ago. Gengis Khan and co. may have brought it with them as they thundered and plundered toward the western European countries. Since it is not a heated food product, the vitamin C in the cabbage is retained, and it lasts for a long time in unrefrigerated conditions making it great food for sailors to avoid scurvy. It is now firmly ensconced in Eastern European cultures (German, Jewish, Dutch etc.) as part of their national gastronomic identity.

You don’t need much to make sauerkraut. At it’s most basic, it’s pounded cabbage and salt in a crock or jar, though herbs, spices or other vegetables could be added to fancy it up. But before we get to the recipe, let’s look at what’s really going on it there, because it’s not magic, it’s microbiology.

If you look at a nice clean green or red cabbage, all you see is a densely packed, slightly rubbery head of leaves. What you don’t see because they are too small, are the millions of local bacteria and yeasts that cover the vegetable’s outer surfaces. We are also covered with the same microbiota (micro = small, biota = life), as are the inside surfaces of our gastrointestinal tract. Our insides are actually continuous with the outside if you think about it. Our microbiome is defined as the genetic material of the microbes inside us, but the words are used interchangeably. (It’s grammatically and scientifically slightly erroneous, but whatever gets the message across…)

Our microbiota, the microbes inside us contains viruses, bacteria and yeasts in varying amounts. Here’ s the size difference between them. There’s a whole conversation that can ensue about the fact that they are all different microbial families which react uniquely. A huge example would be antibiotic sensitivity. Antibiotics have been designed to target bacterial cell coats ONLY. They have no effect on viruses or yeasts, which are totally different organisms. Legislators not understanding this could have a hugely ignorant and negative impact on public health.

Speaking of public health, here’ s a great article from Harvard Health about washing one’s hands. Is washing hands really useful? OMG YES. Simple answer to everything? NO - read the article. But when in doubt (and even when not!) wash your hands with plain ole’ soap and water for 15-20 seconds to wash bacteria off the skin, and dry your hands. Wet hands spread things more easily. Antibacterial soaps aren’t that different from regular soap, it turns out.

If you look at a microbial timeline in sauerkraut with a particular salinity and temperature, you’ll see one organism initially predominate, creating an environment favorable for another to take over. Reducing the pH is an important first part of the timeline to avoid pathogens taking a hold. In turn, early species adjust the environment for others to proliferate and so on until a final pH, microbial and flavor environment stabilizes. It’s mostly lactobacillus species that survives eventually. We taste it, say YUMMY! and put the whole thing in the fridge. The cooler temperature slows fermentation to a crawl such that your refrigerated jar of sauerkraut becomes slowly more fermented, but you’ll eat it long before it becomes unpalatable.

For nerding out purposes, here is an overview from an NIH paper:

“Canonical sauerkraut fermentation begins with the initial proliferation of Leuconostoc mesenteroides, which rapidly produces carbon dioxide and acid. This quickly lowers the environmental pH, inhibiting the growth of undesirable microorganisms that might cause food spoilage while preserving the color of the cabbage. The action of L. mesenteroides changes the fermentation environment so that it favors the succession of other LAB (lactic acid bacilli), such as Lactobacillus brevis and Lactobacillus plantarum. In traditional sauerkraut production, this process proceeds at 18 °C for roughly one month. The combination of metabolites that these organisms produce leads to favorable sensory qualities—the unique flavors, aromas, and textures associated with fermented foods.”

So, in an anaerobic (oxygen free) environment, Leuconostoc mesenteroides (lowers PH rapidly, makes acidic) —> —> mostly Lactobacillus brevis and Lactobacillus plantarum (salt tolerant) and they create an environment that inhibits other types of microorganisms.

food source + microorganisms + time = FERMENT

In this case, the food is the sugar in cabbage leaves, The microorganisms are found on the surface of the leaves, the equipment, our hands and in the air, it takes 1-3 weeks, and the resulting ferment is sauerkraut!

Lets make some! Here’s the recipe.

OK, now you have sauerkraut, what to do with it?

1) Eat it. It’s great as a side dish, or on top of salads, thrown into soups or drained and in a sandwich. On of my favorites is to put it on top of a piece of grainy sourdough bread, cover it with cheese (try manchego or piave vecchio) and then toast it under a broiler. The salty savory flavor goes pretty much anywhere. I sometimes eat it alone as a snack with chopsticks. When I run out of fresh vegetables (infrequent, but it does happen). I’m relieved that my sauerkraut is always there for me.

2) Use it in recipes; it goes very well with pork. My friends makes an amazing bratwurst buried in sauerkraut. This is similar, but use your own sauerkraut, don’t rinse it and then don’t add the extra salt. It’s also just great without meat. Remember that if you cook sauerkraut, the flavor remains, but you’ll kill the probiotic quality.