Mildly sweet, slightly tart and wonderfully bubbly, this homemade soda gets its probiotic fizz from water kefir and its vivid red color from sweet cherries. It's like a homemade cherry soda, but without all the sugar or food dyes.
Drop the cherries evenly into two (16-oz) flip top bottles.
Whisk the brewed water kefir with sea salt and cream of tartar in large pitcher, and then pour it into the bottles over the cherries. Allow it to culture at room temperature 1 to 3 days.
Transfer to the fridge where it will keep for 2 weeks. Strain and serve chilled over ice.