1
Prepare the brine. Stir 20 g of unrefined sea salt into 400 ml of lukewarm water until it has completely dissolved. That is a 5% brine, which is at the strong end for a vegetable ferment and is deliberate here: beetroot is dense and sweet, and a weaker brine lets it go slimy before it goes sour.
2
Assemble the kvass. Place the sliced beetroot, garlic, bay leaves, allspice berries, and peppercorns in the clean glass jar.
3
Add the brine. Pour enough brine into the jar to completely cover the ingredients. Ensure everything is submerged under the liquid to prevent spoilage.
4
Ferment the kvass. Close the jar loosely or with an airlock and store it away from direct sunlight at room temperature.Allow the fermentation to proceed for 7 to 10 days. Check the aroma and taste every few days.
5
Finishing up. Once the kvass has developed a tangy, earthy flavour, remove the beets and other solids from the liquid. You can use a sieve for separation.Transfer the kvass to the fridge to slow down the fermentation. It will keep for a few weeks.