Kombucha Brewing Calculator

How It Works

Kombucha is fermented sweet tea made with a SCOBY (Symbiotic Culture of Bacteria and Yeast). The first fermentation (1F) takes 7-14 days at room temperature (68-85°F). During 1F, bacteria and yeast consume sugar, producing organic acids, CO2, and a small amount of alcohol (<0.5%). The pH drops from ~4.5 to 2.5-3.5 — taste daily starting at day 5 to find your preferred sweet-tart balance. Second fermentation (2F) in sealed bottles for 2-4 days builds carbonation. Black tea provides the most nutrients for the SCOBY. Always reserve 10-15% of finished kombucha as starter for the next batch — this acidic starter prevents mold.