As with many fermented products, a trace amount of alcohol may be present in kombucha. After it is bottled, in the absence of oxygen, the yeast will continue to degrade sucrose and fructose, and is capable of increasing carbon and producing alcohol levels greater than 0.05%. Controlling factors, including temperature, acidity, glucose availability, and complementary proportions of yeast and bacteria aid in limiting anaerobic alcohol production after packaging.
Option 1: Pasteurization will kill the culture, preventing carbon dioxide or alcohol from building up in the bottles. To pasteurize, heat the kombucha to 180°F (82°C) and bottle immediately. After 30 seconds invert bottle and hold for another 30 seconds. Allow bottles to cool. Pasteurized and bottled kombucha with a pH less than or equal to 4.2 is shelf stable.
Option 2: This method relies on refrigeration and antifungal preservatives to minimize hazards and spoilage. Add 0.1% sodium benzoate and 0.1% potassium sorbate to kombucha with a pH less than or equal to 4.2. Keep refrigerated until use. A refrigerated shelf life will need to be determined based on eventual yeast growth,carbon dioxide and alcohol production.
Option 3: This method relies on refrigeration alone to minimize hazards and spoilage. Keep refrigerated until use. A refrigerated shelf life will need to be determined based on eventual yeast growth,carbon dioxide and alcohol production.
Adapted from: Nummer B.A. (2013) Kombucha Brewing Under the Food and Drug Administration Model Food Code: Risk Analysis and Processing Guidance. Journal of Environmental Health, 76(4): 8-11.