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You should make fermented veggies—for science

The science behind sauerkraut.

sauerkraut

You, yes you, can ferment foods at home.

“Will the cake stand hold five pounds of cabbage?”

These are the thoughts that occur to you when you live in a small New York City apartment and you’re trying to figure out how to make sauerkraut without a specialized fermentation crock—and with a limited number of appropriately-sized mason jars and mixing bowls. As a further complication, the containers had to be glass or ceramic, because metal doesn't take well to a salt brine.

My beloved 6.5-gallon food-safe buckets, in which I used to make beer, had vanished during a move. But the lid of my glass cake stand, then acting as an impromptu onion- and garlic-holder, already had practice as a produce container. Flipped upside down, it made a perfectly acceptable large bowl, perfect for a foray into vegetable fermentation.

Though I dream of homemade kimchi, I was starting with the gateway fermentation recipe: sauerkraut, which requires only cabbage and canning salt.

“What the heck is canning salt?” was the question I got most often when telling people my plans for my latest kitchen experiment. Also known as pickling salt, it came highly recommended by Michelle Jarvie, an extension specialist at Michigan State University who fields fermentation and food safety questions from the public (and from journalists like me).

“You need to use canning salt,” Jarvie says, explaining that many other salts include iodine and other additives in the mix, while canning salt doesn’t. And that’s important. “Iodine will kill the organisms that you want in there,” Jarvie says.

Those organisms are Lactobacillus, a friendly genus of bacteria that humans use to make everything from yogurt to, well, sauerkraut. They thrive in anaerobic (oxygen-free) environments, where they feed on sugars like those in milk or vegetables and create lactic acid in the process. That byproduct produces that distinctive tangy sauerkraut taste we all love. Lactic acid also keeps more dangerous microbes, such as fungi and molds, at bay. Which is why humans have been using this preparation method to preserve foods since antiquity.

“Fermentation is a pretty foolproof food preservation method if you follow the guidelines for temperature, sanitation, and proper proportions,” Jarvie says. “The organisms that are doing the fermenting outcompete and kill off the harmful bacteria.”

But the Lactobacillus need some help in the process. Just like with other forms of fermentation, you really need to make sure that your workstation, hands, and materials are clean to avoid contaminating your vegetable treasures with unwanted microbes.

“You always want to make sure your equipment is clean and sterile, and that you practice good hand hygiene,” Jarvie says.

So after making sure that your hands, cake stand—or sure, crock, bowl, whatever—and knife are all clean, it's time to get chopping.

I followed the basic sauerkraut recipe from the National Center for Home Food Preservation (though I only plan on making five pounds of kraut, not 25). Jarvie recommends starting with a basic recipe from a source like the USDA or National Center for Home Food Preservation, both of which test their recipes in controlled environments.

I core and finely chop the cabbage into strips, add the three tablespoons of salt that are recommended for a batch of five pounds, and put it all into my chosen container—the aforementioned cake-stand lid. Then, it’s time to really get in there. To help the salt draw water out of the cabbage, you need to mix it thoroughly with your (clean!) hands, pressing and mixing until water starts to get pulled out of the mix. It's a messy process, but surprisingly meditative.

The next step is to keep the nascent sauerkraut in its proper place: deep under the salty cabbage juice, also known as brine. If slivers of vegetable peek above the protective embrace of salt and lactic acid, mold has an opportunity to start growing on these surfaces and then send its polluting roots down into the briny goodness. I weighed down the cabbage with a plate and a plastic bag filled with salty water—that way if it leaks, it won’t drastically dilute the sauerkraut.

The sauerkraut will stand in the kitchen, covered, for about three weeks. I’ll try to keep an eye on the process, but for the most part, the bacteria will do all the work for me. As long as the apartment stays between 70 and 75 degrees Fahrenheit, the fermentation will keep bubbling along. Temperatures any hotter than that risk giving harmful microbes an advantage, and lower ones could drag out the process to as long as five to six weeks.

But the final product is definitely worth the patient wait, the quiet bubbling, and the loss of a cake stand...at least for a few weeks. Next time: Kimchi.

How to make no-frills sauerkraut

Tools

  • Large (at least 1-gallon) glass or ceramic bowl or container
  • Knife and (optionally) a food processor
  • Ceramic plate
  • Gallon Ziploc bag filled with 3 quarts of water and 4 ½ tablespoons of salt OR two clean glass jars filled with water and topped with lids

Materials

  • 5 pounds of fresh cabbage
  • 3 tablespoons of canning or pickling Salt

Instructions

  1. Thoroughly clean all the tools you will be using.
  2. Core and quarter the cabbage and use the knife or food processor to shred it into thin, even slices. Place it in the large (non-metal) bowl or container.
  3. Add salt to the cabbage and combine it thoroughly with clean hands. You should mix it for several minutes, or until it releases enough liquid to completely cover the cabbage.
  4. Place a plate in the container to hold the cabbage under the liquid's surface. Weigh it down with either a plastic bag of salted water or clean glass jars filled with regular water, making sure that all of the cabbage is submerged.
  5. Let the sauerkraut sit for three weeks. During this time, keep the room temperature between 70 and 75 degrees to encourage the quickest fermentation.
  6. When the liquid stops bubbling, your sauerkraut is ready!

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