Water kefir should be naturally effervescent like a soda. If yours is flat and still, it usually means the carbon dioxide (CO2) is escaping or isn’t being produced. Here is the checklist to fix it.
1. Check Your Seal (Most Common)
If air can get out, gas can’t build up.
The Fix: Use Swing-top Grolsch-style bottles. Mason jars often leak gas through the screw lid.
2. The Sugar Factor
Yeast needs sugar to create bubbles. If you drink it immediately after the first ferment (F1), it won’t be fizzy.
The Fix: You must do a Second Ferment (F2). Add 1 tsp of sugar or fruit juice to the bottle before sealing. This is “fuel” for the fizz.
3. Temperature
Yeast sleeps in the cold. If your house is below 20°C (68°F), fermentation slows to a crawl.
The Fix: Wrap your bottles in a towel or place them on top of the fridge (where it’s warmer) for 24-48 hours.
Not sure if your grains are active? Add a handful of raisins to the first ferment. Raisins are packed with yeast and minerals. If they float to the top within 24 hours and have bubbles on them, your yeast is healthy!