Kombucha Not Carbonated: Causes & Fixes
Flat kombucha is one of the most common issues brewers face. Learn why your kombucha lacks fizz and how to fix it.
Quick Answer
Common Causes
Insufficient sugar for second fermentation
Without enough sugar, the remaining yeast cannot produce CO2. Most kombucha needs 1-2 teaspoons of sugar per 16oz bottle for carbonation.
Bottles not sealed properly
CO2 escapes through loose caps or damaged seals. Flip-top bottles with rubber gaskets work best.
Too cold during second ferment
Yeast activity slows significantly below 68°F (20°C). Aim for 70-80°F for active carbonation.
First ferment went too long
Over-fermented kombucha has less residual sugar and weaker yeast, making carbonation difficult.
Not enough time in second ferment
Most kombucha needs 2-4 days of second fermentation. Patience is key.
How to Fix It
Add more sugar
Add 1/2 to 1 teaspoon of sugar per 16oz bottle and reseal. Wait 1-2 more days.
Check bottle seals
Ensure flip-top gaskets are intact or screw caps are tight. Replace damaged seals.
Move to a warmer location
Place bottles in a 72-80°F area. A heating mat can help in cold weather.
Wait longer
Give it another 1-3 days before refrigerating. Check daily for pressure.
How to Prevent This
- Use proper flip-top bottles designed for carbonated beverages
- Add fruit juice or sugar at bottling time
- Maintain consistent temperature during second ferment
- Do not over-ferment the first fermentation
- Keep bottles at room temperature for 2-4 days minimum
Frequently Asked Questions
Can I re-carbonate flat kombucha?
Why does store-bought kombucha have more fizz?
Do I need special bottles for carbonation?
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Disclaimer
This content is for educational purposes only and is not medical advice. Fermented foods affect individuals differently. Consult with a healthcare provider before making significant dietary changes, especially if you have health conditions. Practice proper food safety when fermenting at home.