Carbonating Kombucha, Pop, and Cider

If you carbonate kombucha, pop, cider, or spritzers, your bright-tank problem is different from a brewer’s: your product arrives warm.

The warm-tank problem

On a real kombucha plot, the product hit the tank at over 12 degrees Celsius, far too warm to carbonate. You want the product as close to 0 degrees as possible for CO2 to dissolve. So the first job is patience: chill before you carbonate.

Start temperature and the mixing bounce

FizzWizz’s start temperature setting is typically 3.5 degrees; this client set 5. At 5 degrees a pre-scrub is acceptable, but carbonation is not. When the CO2 first kicks on, it stirs the tank. Warmer product drawn down around the temperature sensor makes the reading jump, the unit pauses, then restarts as the tank mixes and chills. You’ll see that little disturbance on the plot. It’s normal and it resolves itself.

The vacuum trap

As a warm tank chills, the pressure inside falls. Drop it carelessly and you can pull a vacuum on the tank. The clean solution this client used: leave about 1.5 PSI in the tank as a floor, so the temperature drop can never take it negative.

Then it’s automatic

Once the product is down to temperature and stable (2.29 degrees on this plot), the pre-scrub runs (target 3 PSI, then vent to 1 PSI) and carbonation starts on its own, with no buttons to press. This run shut off at 11.24 PSI against a target of 11.22: within 0.02 PSI, with the target continuously recalculated as the tank temperature moved.

Carbonating anything besides beer? Talk to us. We set up kombucha, cider, and soda tanks every week.