I have seldom fermented beets on their own; for some reason these roots, when brined, seem more inclined to grow mold than to sour. But an ample harvest of beets from my garden this year inspired me to try making beet kwas, or kwas burakowy, a popular Polish tonic.
Kwas (or kvass) is a sour, refreshing fermented drink enjoyed throughout eastern Europe. The typical version, made from bread and water, may date to the tenth century. According to the Polish Ministry of Agriculture and Rural Development, kwas made from beets became popular in Poland in the 1920s. Deep red and slightly viscous, it has been traditionally used in a Christmas Eve borscht, but it is also drunk straight as an energy booster.
Today beet kwas enthusiasts make numerous claims about the health benefits of their favorite drink. Beets are full of antioxidants; they help prevent cancer and arteriosclerosis; they are good for colds, weakness, anemia, and recovery from antibiotic use. They support the kidneys and liver. They lower cholesterol; they improve immune function; they contain vitamins A, C, and B (including folic acid) and the minerals iron, potassium, and calcium. Fermenting the beets makes these nutrients more available to the body. Beet kwas “purifies” the blood and the liver, lowers blood pressure, and boosts stamina during exercise.
I can’t vouch for any of these claims, but a crimson vegetable that tastes like dirt has got to be good for you, right? Fermentative bacteria add their own nutrients and balance the dirty taste with lactic and acetic acid. Both the flavor and healthfulness of beet kwas can be enhanced with the seasonings of your choice—for Poles, garlic (always!), allspice, black pepper, sweet bay, fennel, horseradish, carrot, and celery. Americans who have recently discovered beet kwas favor sweet and fruity flavorings—lemon, orange, ginger, and sweet spices.
Finally, you add rye bread. Poles traditionally boost fermentation—even when making cucumber pickles—by laying a stale heel of sourdough rye bread on top of the brine. I hoped that adding a slice of my own homemade sourdough rye would get me sour rather than moldy beet tonic.
I followed the method of Robert and Maria Strybel, Polish-Americans who first published their Polish Heritage Cookery in 1993. Here is my version of their simple recipe:
Kwas Burakowy (Beet Kwas)
1 pound red beets, peeled and sliced thin
1 large garlic clove, chopped
½ teaspoon sugar
1½ teaspoons pickling salt
1 slice sourdough rye bread
5 cups lukewarm water (filtered or boiled, if it has been chlorinated)
Put the beets into a 2-quart jar (I used a mason jar). Add the garlic, sugar, and salt. Place the bread on top, and pour the water over. Cover the jar loosely. (I used a plastic mason-jar lid but screwed it on only part way; the Strybels advise using cheesecloth or a dish towel.) If the beets float to the surface, weight them. (Mine didn’t float, but if they had I would have weighted them with one of my glass candle holders.) Let the jar stand at room temperature.
After four days, begin tasting the liquid. When a pleasant tartness has subdued the dirty taste—for me, this took six days—strain the liquid. (Although neither the Strybels nor other Polish writers whose works I consulted advised this, I squeezed the bread before discarding it. I also saved the sliced beets, to use slivered in salads, although they had lost some of their color.)
You should have about 1 quart kwas. Pour it into a bottle, cap the bottle, and chill it.
For health, Poles say, drink a cup of beet kwas once or twice a day. Some say to start with just an ounce or two and gradually increase the dose to 8 eight ounces.
I drank a small glass of my kwas each morning before breakfast until the bottle was empty. Although I usually balk at the thought of a chilled drink in the morning, I’ve missed my kwas since running out. Happily, there are still more beets in the garden, ready to harvest and to transform into kwas.