Vivid in color but delicate in flavor, this fruit kvass makes a delicious summer drink. It has a slightly acidic, effervescent edge that makes it super refreshing. This recipe is adapted from Strawberry Kvass from Elena Molokhovets' A Gift to Young Housewives.
Whisk the water, salt, and honey together in a medium-sized pitcher, and then pour over the berries, allowing 1-inch headspace and discarding any remaining brine. Seal the jar tightly, and shake.
Allow the fruit kvass to ferment at room temperature for about 3 days, shaking it daily and burping the jar twice a day. The kvass is ready when it lets out a hiss of air when you burp the jar.
Strain the kvass through a fine-mesh sieve, discarding the fruit. Transfer to a clean bottle and serve right away or store in the fridge up to 1 week.