This article and recipe was originally featured in the You Can Ferment That column of Zymurgy magazine.
By Amahl Turczyn
Kvass is a Slavic beverage typically made with baked rye bread, water, and sometimes barley or wheat malt flour that is mixed to a loose, liquid consistency, lightly warmed to encourage enzymatic starch conversion, and then allowed to ferment for several days. It is never boiled, so in addition to natural yeasts present, there are often lactic bacteria. It’s usually not classified as an alcoholic beverage, as alcohol content is kept under 1 percent by volume.
After fermentation, the enzyme-, yeast-, and bacteria-rich brown liquid is poured off and bottled for consumption; some people add fruit, herbs, or spices. The solids are kept as a kind of sourdough starter for the next batch of sour rye bread. It’s a nourishing beverage that, like makgeolli in Korea, is available commercially, but the best and healthiest versions are homebrewed.
Historically, kvass was said to be the chief beverage of monks and peasants, who preferred it to water. But, as with many probiotic fermented beverages, it evolved into endless varieties, some without rye bread as a base. We will focus on one of the healthiest and most attractive versions of kvass, one made from raw beets rather than baked bread.
While the earthy flavor of beets isn’t to everyone’s liking, beet kvass is an excellent liver tonic, and therefore popular as a cleansing detox brew among brewers and other beer enthusiasts. This recipe, in particular, is flavored with garlic and ginger in addition to beets, and the resulting tart, earthy beverage makes for a wonderful pick-me-up on brew days when you want to stay focused and alert. It’s also great for heart and gut health.
Beet kvass is very easy to make, especially if you have a starter brine from another lactic-acid-bacteria-based food fermentation. Sauerkraut juice, kimchi juice, kefir whey, and fermented pickle juice can all be used to jumpstart kvass fermentation and can turn the typical one-week ferment into just a few days. Personally, I like to dip into my jar of fermented serrano peppers, as the slight chile kick goes great with the garlic, ginger, and beet flavors.
Beets grown in your own garden are, of course, preferred, but organic beets from the farmers market or grocery store work fine, too. Cut the tops off of three medium-large beets and save those greens for eating (they are also tremendously good for you, so don’t just compost them). Pick the hairy roots off each beet and scrub the roots well under cold water to remove any soil. Don’t peel them; most of the natural yeasts and beneficial bacteria are on the skins of the raw roots. Finally, dice them into roughly 1-inch cubes. It doesn’t have to be pretty. You don’t want to shred or puree them, though, because that releases too much sugar too quickly, and you’ll end up with alcoholic beet beer.
Mix the Brine
Kvass brine requires less salt than pickle brine—only a teaspoon of pure sea salt per quart of carbon- or reverse osmosis–filtered water (5 mL salt per liter of water). Dump the beet chunks into a clean Mason-type quart jar, sprinkle in the salt, and fill almost to the top with water. At this point, you can also add a few cloves of fresh, peeled garlic and a couple slices of fresh ginger root. The ginger, in particular, is a good source of natural yeast and enzymes and will help with the fermentation as well as add its warming, invigorating flavor.
Pitch a Starter (Optional)
As with any lactic fermentation, getting the pH down quickly is beneficial. There are natural bacteria and yeast on the beet skins, and they will ferment spontaneously, but depending on ambient temperatures, they may take several days to get started. You don’t need much starter—just a couple of tablespoons of active brine, whey, or kraut/kimchi juice will be plenty for a 1-quart batch.
Cover and Ferment
You’ll want a tight-fitting lid for your fermenter, or a Mason-jar airlock specifically designed for home food fermentation. Keeping oxygen out is important since the brine is relatively low in salt. Place the jar in a dish or something to catch any escaping juices (beet juices are wonderful at staining countertops), make sure all vegetable solids are submerged, and crank down the lid tightly. Then leave at ambient temperatures for four to seven days, checking the kvass daily and burping off any pressure that may form. You should be able to see bubbles rising from the ferment after a day or two.
Begin tasting the liquid after day three. It should develop a pleasant lactic tartness. When the acidity meets your approval, simply strain the liquid into another container and enjoy. You can do a couple of subsequent batches from the same beet solids by simply repeating the brine addition and leaving the same jar to referment; they will ferment faster, but the kvass will have a lighter flavor and color.
In hot climates, mold may develop; if that’s the case, or if you notice the kvass becoming viscous or slimy, it’s best to toss the batch and start over. You may choose to add the fresh juice of half a lemon to the brine, which will lower the pH faster (and it tastes great with the beets.)
That’s it! Try this brilliant crimson elixir with ice and a lemon wedge, perhaps with a shot of peppery first-press olive oil. You can also use golden beets for this recipe, or feel free to experiment with other root vegetables along with the beets: radish, horseradish, carrots, and turnips are all options. You can also add herbs and spices to change things up if you find yourself making kvass regularly. Fresh dill with red beets is particularly good. Kvass is a tasty and healthy probiotic fermented drink—and your liver will thank you for it.
Beet Kvass Recipe
Batch volume: about 0.75 qt. (700 mL) liquid from a 1 qt. (1 L) ferment
- 3 medium-large, fresh beets
- 1 tsp. sea salt
- filtered water
- 2 Tbsp. starter liquid (fermented pickle brine, kefir whey, sauerkraut, or kimchi juice), optional
- 2–3 fresh, whole garlic cloves, optional
- 2 fresh ginger root slices, optional
- other herbs or flavorings (fresh dill, black peppercorns, mint, raisins, etc.), optional
1-quart Mason-style jar with tight-fitting lid or airlock
Trim beets of tops and roots, but don’t peel. Scrub thoroughly and dice into 1″ (2.5 cm) cubes. Place beets in sanitized 1 qt. (1 L) Mason-style jar along with garlic and ginger, if using; sprinkle beets with sea salt, then pour filtered water over beets. Top off with 2 Tbsp. active starter liquid, if using. Cover tightly with lid or airlock—if using lid, remember to burp the gasses off daily. Ferment at ambient temperatures (65–70°F or 18–21°C) for 4–7 days until tart aroma develops. Strain off liquid to another container and refrigerate, using as needed. Jar may be refilled with fresh brine for subsequent batches. If mold develops, or liquid becomes slimy, discard and start over.
Amahl Turczyn continues to brew and write at his home in Lafayette, Colo.