First, beets are a period food in many of the cultures that have representative personas in the SCA. A relative of chard, originally more in the shape of a carrot and much more bitter than the cultivated bulb we know today, beets have been used in everything from medicine to cosmetics. Beet remains have been found not only painted on brothel walls, but in the ashy remains of Pompeii. The book Cookery and Dining in Imperial Rome includes several treatments of the humble veggie as does The Art of Cooking by Apicus (1c AD).
See this article from Just Beet It for more information on Beet History
Second, I love the fact that Ukraine has applied for UN cultural status for Borscht. Beets thrive in cold climates, as do many root vegetables, and have been found in archaeological excavations. I have found reference to evidence of seeds in the book The Early Slavs by P.M. Bradford, which I am still reading at this point in time - it's a big book - and I'm looking for more references which I will post when I find them. Searching papers has become somewhat challenging as I'm cut off from accessing some of the Archaeological Institute papers which were previously available in English translation from Russia and the Ukraine. World events have been affecting what is available and accessible online since roughly 2018.
So let's talk Kvass. Kvass in its most well known format is made by fermenting dark rye bread. Now it is also called "Children's Beer" with alcohol content of 0.5 to 1% and is sold via barrel shaped stands all over Russia. I've been able to find notes of it also being flavored with dates and raisins which both would have been available via trade during period. If you doubt that such ingredients were available to the Eastern Slavs I highly encourage you to read Ibn Fadlan.
In period, it was much safer to drink than water since the fermentation process killed off the bad bacteria. So many of the cultures we know throughout history chose to drink fermented beverages over water for this very same reason.
Beet Kvass seems to be something that is tied to the Ukranian region of the Eastern Slavic area, and is known as a probiotic and source of vitamins. There are three simple ingredients, beets, water and salt. Sea salt is recommended for use as iodized salt will inhibit the development of the probiotic bacteria we are after.
For this first experiment I used the recipe from Feasting at Home and the Easy Fermenter from Nourished Essentials. I will be using the recipe recommended 2 weeks for fermentation. I ended up using 5 cups of water, 5 tsp of sea salt and 4 cups of washed skin-on diced beets.
Next update in 2 weeks!