Why is my bottled kombucha not fizzy even after second fermentation?

Question

Why is your bottled kombucha not fizzy? Troubleshoot the common reasons for a flat brew, from weak starter to improper sealing and temperature.

Answer 1

Your kombucha might not be fizzy due to insufficient sugar for the yeast to consume, a weak SCOBY, temperature fluctuations, or a leaky bottle. Ensuring proper conditions and a healthy SCOBY are key to carbonation.

Detailed Explanation:

The fizz in kombucha comes from carbon dioxide, a byproduct of yeast consuming sugar during fermentation. If your kombucha isn't fizzy after the second fermentation, several factors could be at play:

1. Insufficient Sugar: The yeast needs sugar to produce carbon dioxide. If you didn't add enough sugar during the second fermentation (usually fruit juice, fruit pieces, or a small amount of plain sugar), the yeast won't have enough fuel to create fizz. A good starting point is about 1-2 teaspoons of sugar per 16-ounce bottle.
2. Weak SCOBY/Yeast: A weak or inactive SCOBY (Symbiotic Culture Of Bacteria and Yeast) means less yeast activity. This can happen if your SCOBY is old, stressed, or hasn't been properly cared for. Make sure your starter tea is strong and healthy.
3. Temperature: Yeast thrives in warm environments. If the temperature is too cold (below 68°F or 20°C), the yeast will be sluggish and produce less carbon dioxide. Aim for a temperature between 70-78°F (21-26°C) for optimal fermentation.
4. Leaky Bottles: If your bottles aren't properly sealed, the carbon dioxide will escape, resulting in flat kombucha. Use bottles specifically designed for kombucha or other carbonated beverages, ensuring they have a tight seal. Flip-top bottles are generally preferred.
5. Fermentation Time: Sometimes, it simply takes longer for the kombucha to carbonate. Be patient and allow the second fermentation to continue for a few more days, up to a week or even longer, depending on the temperature and other factors.
6. Low Mineral Content: Yeast needs minerals to thrive. Using filtered water that is too pure can sometimes hinder fermentation. Try using spring water or adding a pinch of unrefined sea salt to your brew.

Pro Tip:

'Burp' your bottles carefully during the second fermentation to release excess pressure and prevent explosions, but avoid opening them completely unless necessary, as this will release the carbon dioxide you're trying to build up.