Fermenting and Storing Kraut in Small Jars, without Pasteurization or Refrigeration

cabbage-heads-2-croppedI’ve more than once seen Extension home-ec agents roll their eyes when asked if it’s possible to store sauerkraut in the same jar in which it has fermented, with no heating or chilling. Where do such ideas come from? the agents ask.

From Extension’s mother agency, the U.S. Department of Agriculture, of course! Randal Oulton recently sent me a 1936 USDA press release, intended for radio broadcast, about how USDA researchers had made and stored sauerrüben—fermented shredded turnip—in just this way:

Shredded [and salted] turnips were packed in 2-quart glass jars, which held approximately 4 pounds of turnips each when packed firmly. Because of the pressure produced by the gas released during the initial fermentation, the lids of the jars had to be left loose. By this means the gas was allowed to escape, yet at the same time a sufficient concentration of carbon dioxide to prevent aerobic spoilage was maintained over the fermenting material. As the evolution of the gas lifted considerable quantities of the juice to the top of the jar, causing it to overflow, the jars were placed in enameled pans until the period of gas formation was over. Once each 24 hours the lids were removed, the shreds were pushed down into the jars by means of a wooden spoon or blunt wooden stick, the lost juice was returned to the jars, and the lids were replaced.

I wonder if the researchers strained out the fruit flies before returning the juice to the jars. Anyway, the report continues:

As soon as the gas ceased to be given off, which required about 4 days, the jars were sealed tight and stored at room temperature. The fermentation was generally completed in 12 to 14 days, and the product was then ready for use. The product put up in this manner has been kept for 3 years and is still in excellent condition, although heat has not been applied.

Presumably the jars were stored in a cool place such as a cellar and not in a really cold place like a refrigerator. We aren’t told what kind of lids the researchers used and whether the lids formed a vacuum seal. In any case, the method worked, and the writer suggests trying it with 1-quart as well as 2-quart jars. The article makes no mention of exploding jars, which the home-ec agents always warn about.

I would certainly prefer to try this method over another recommended in the same piece: After fermenting the shredded turnip in open stone jars, you cover the surface with mineral oil.

Have you tried making and storing sauerkraut or sauerrüben in small jars without heating or chilling? How well did your method work? I’d love to hear your stories.

Can Pickles Cure the Flu?

In an article in Letters of Applied Microbiology, Japanese scientists report that feeding a pickle microbe to mice infected with the flu alleviates the rodents’ symptoms. The scientists previously found that this same bacterium, already in commercial use as a probiotic, can ease acute gastroenteritis caused by Vibrio parahaemolyticus, which sometimes occurs in raw seafood, and irritable bowel syndrome. But the flu results have gotten by far the most attention from the media. UK’s Daily Express, for example, hailed the “New Wonder Cure for Killer Flu.” Picklers around the world may wonder, Is this miracle drug in my pickle crock? Can it cure me of the flu, too?

Actually, the microbe hasn’t cured anybody’s flu. But it did reduce weight loss in infected mice and reduce other symptoms of mouse malaise, such as ruffled fur and lethargy. In other words, the mice treated with the bacterial extract were a little less sick than the untreated ones (that is, until all the mice were forced to inhale enough carbon dioxide to kill them).

The bacterial extract hasn’t been tested in humans. We don’t yet know whether it would alleviate human flu symptoms, and we certainly can’t bet that it would prevent or cure influenza. And we should keep in mind that two of the scientists who wrote the article work for Kagome, the company that markets the microbe, although they declared no conflict of interest. Still, the results are promising.

The name of the miracle bacterium, Lactobacillus brevis, may ring a bell. If you make fermented pickles, you’ve surely cultivated the species. L. brevis predominates in the last stage of fermentation of sauerkraut and brined vegetables. This bacterium is also among the lactic-acid-producing species found in tibicos (water kefir) “grains”; it is, in fact, responsible for producing the polysaccharide gel of which tibicos grains are composed. Among brewers, unfortunately, mention of L. brevis provokes dread, because the species can spoil beer by souring it (although at the moment, oddly, soured beer is nearly as trendy as soured vegetables).

To understand how L. brevis may affect human health is to grapple with the theory of probiotics—that is, live microbes consumed to promote health through their effects in the intestines. L. brevis is one of the lactic-acid-producing bacteria found in healthy human intestines, vaginas, and feces. In recent years scientists have produced plenty of evidence that a healthy immune system depends on a healthy balance of intestinal microflora. When the balance gets out of whack—from the use of antibiotics, from improper diet, or even from emotional stress—we may be able to alleviate the problem by ingesting good bacteria.

Even assuming that the Japanese bacterial extract will prove effective in humans, whether eating pickles will vanquish your flu symptoms is hard to say. First, for L. brevis to be present at all, your pickles must be fully fermented and unpasteurized. Assuming L. brevis is present, it may be slightly different from the strain the Japanese scientists have studied, a strain known as L. brevis KB290. The scientists isolated KB290 strain from suguki pickles, that is, pickled suigukina, a kind of turnip grown near Kyoto. Suguki is one of many traditional Japanese pickles that are identified with a particular city, with particular varieties of produce grown in the region, and even with particular producers. But although the Japanese rightly view suguki as unique, it is made much like other fermented pickles: The turnips are peeled, cut, and briefly salted so that the slices become flexible. They are next packed firmly into buckets, layered with salt, and then weighted. Then they are drained, and they are weighted again until fermentation is complete. They are not enhanced with garlic, chile, or other seasonings. The only really remarkable thing about these pickles is the way they are weighted, using a big stick called a tenbin; have a look at the photo here. Even sans tenbin, fermenting turnips from your garden or local market would probably produce a pickle similar in taste and microbial content to Kyoto’s suguki.

L. brevis would be present in your own turnip pickles, but don’t count on breeding the strain KB290. A strain, to a microbiologist, is derived from a single colony and has been protected from contamination through carefully controlled procedures. These procedures make it possible to test the strain for efficacy and safety and, assuming the strain passes the tests, to market it as efficacious and safe. A strain is not, however, different enough from other strains of the same species to be called a subspecies. And no strain would last in nature. In nature, bacteria undergo continual mutations and lose and gain genetic material. Bacteria thrive in communities made up not only of multiple strains of the same species but of multiple species as well.

Japanese scientists no doubt isolated and tested multiple L. brevis strains before selecting KB290 for marketing as a commercial probiotic. KB290 must have performed better in meeting the requirements of any effective probiotic, for example, in adhering to intestinal cells, in persisting and multiplying, and in producing substances, such as acids, that curb the growth of pathogens. KB290 had to work reliably in all of these ways so it could be marketed on its own, as a drug.

Your pickle crock, in contrast, hosts various strains of L. brevis along with other species of Lactobacillus and fermentative bacteria in other genera, such as Leuconostoc and Pediococcus. Since bacteria are genetically fluid, their diversity is more important to your health than the identity of any particular strain in the crock. Lactic-acid-producing bacteria in naturally fermented foods increases the spectrum of genes available to your intestinal microflora regardless of whether specific strains are able to take up permanent residency in your gut.

So, go ahead and pickle some turnips. Make plain sauerruben, as instructed below, or try my recipe for spicy Korean pickled turnips, sunmukimchi (The Joy of Pickling, 2nd edition, page 67). If you get the flu this winter, eating some of your own pickled turnips just might help you get better faster. In any case, turnips may help keep you healthy generally, especially if you eat the vitamin- and calcium-rich green turnip tops.

Sauerruben

5 pounds turnips, peeled and shredded (with a kraut board, food processor, or grater)
3 tablespoons pickling salt, plus more for the brine

In a large bowl, mix the turnips with 3 tablespoons pickling salt. Pack the mixture firmly into a 3-quart or gallon jar. Push a gallon-size freezer bag into the jar, and fill it with  brine made of 1 1/2 tablespoons pickling salt to each quart of water. Seal the bag. Set the jar in a place where the temperature remains between 60° and 75°F.

After 24 hours, check to make sure that the turnips are well submerged in their own brine. If they aren’t, add some fresh brine (1 1/2 tablespoons pickling salt per 1 quart water) to cover them well. If any scum forms within the jar, skim it off and rinse and replace the bag.

After two weeks, begin tasting the sauerruben. It will be fully fermented in two to four weeks at 70° to 75°F, or within four to six weeks at 60°F. When it’s ready, remove the bag, cap the jar, and store it in the refrigerator or another very cool place, tightly covered.