The first fermentation (F1) of kombucha typically lasts between 7-30 days, depending on temperature, SCOBY health, and desired tartness. Taste-test regularly after 7 days to determine when it reaches your preferred level of acidity.
The first fermentation, or F1, is where the magic of kombucha happens. During this stage, the SCOBY (Symbiotic Culture of Bacteria and Yeast) consumes the sugar in the sweet tea and transforms it into a tangy, slightly acidic beverage. The length of F1 is influenced by several factors:
Temperature: Warmer temperatures (around 70-75°F or 21-24°C) speed up fermentation, while cooler temperatures slow it down. Avoid extreme temperatures, as they can harm the SCOBY.
SCOBY Health: A healthy, active SCOBY will ferment faster than a weak or new one. A larger SCOBY also tends to ferment more quickly.
Desired Tartness: The longer the fermentation, the more tart and vinegary the kombucha will become. Start tasting your kombucha around day 7. Use a clean straw to draw a small amount from under the SCOBY. Continue tasting every day or two until it reaches your preferred level of tartness.
Starter Tea: Using a larger amount of strong starter tea from a previous batch can also speed up the fermentation process and help prevent mold growth.
Once the kombucha reaches your desired tartness, it's ready for bottling and flavoring in the second fermentation (F2), or you can drink it as is.
Always reserve at least 1 cup of unflavored kombucha from each batch to use as a starter for your next batch. This ensures a strong and healthy fermentation process and helps maintain the acidity needed to prevent unwanted mold growth.