The 'quick carb' (high PSI, shake keg/CO2 stone) vs. 'low and slow' carbonation ("set it and forget it") debate seems to be hinged on the issue of CO2 hydration/hydrolysis (not sure which, will correct when someone tells me). Beer that is carbed slowly will have hydrolyzed CO2, while beer that is 'quick' carbed will have unhydrolyzed CO2. The parallel to this would be soda that is served from a fountain (carbed h2o mixed with syrup) vs. a soda in can/bottle.

Does it take a full 2 weeks (or some other duration) for CO2 to hydrate/hydrolyze, or could a brewer give the carbonation a head start (by shaking keg at higher PSI), then wait, say one week for the dissolved CO2 to round out?

  • 1
    Is there any supporting evidence for the two sides of this debate? My understanding (by no means comprehensive, admittedly) is that at equilibrium, the ratio of carbonic acid (the hydrate of carbon dioxide in aqueous solution) to carbon dioxide is only ~1/600. Aug 11, 2015 at 19:44

1 Answer 1


Franklin is right about how much carbonic acid is actually in the beer. The formation of carbonic acid is pretty much irrelevant. But...

The formation of carbonic acid isn't that slow, it's just hard to get CO2 into solution without some agitation. Soda fountains mix CO2 and water just before the soda comes out, and by the time it hits your cup it's all fine.

  • right, but the two absolutely have different mouthfeels, which bleeds over into the taste of the beverage. My question is, what is the minimum amount of time needed to get the mouthfeel of a can of soda, or slow-force carbed beer?
    – Pietro
    Aug 12, 2015 at 17:33
  • My best guess is that a longer wait will always be better, because the beer will have more time to clear up yeast and haze. With fewer nucleation points in the beer, more carbonation will make it to your mouth, for more perceived carbonation / mouthfeel.
    – Pepi
    Sep 13, 2015 at 1:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.