For some reason today, carbonated beverages have been fizzing up more than usual. It's happening with beer and club soda. Very strange, no gremlins either - the beer was from the back of the fridge, been there since yesterday. The club soda was still for plenty of time.

I was thinking low atmospheric pressure could be at hand. There are stratocumulus clouds in the sky, the AC is on. In Chicagoland area.


This is physics rather than Earth Sciences, but differential pressure between tinned liquid and atmosphere is by far the dominant factor. In Scotland I remember opening a can of 7-up at sea level with almost no effervescence. Then I climbed Ben Nevis, 1344 metres, and celebrated reaching the summit with another can. The resulting 'geysir' ejected about half the can in spectacular fashion. Temperature also has an effect in that the solubility of CO2 on a cold day, say 10 deg C, is about 30% more than on a hot day of ~30 deg C. So if the outside temperature is warmer than at the time the drink was canned, then there will be an excess of free gas that has come out of solution, but is still in the can waiting to be released. If we say two grams of excess CO2 in the can, that will yield about a litre of gas at one atmosphere and 21 deg C.

I'm wondering what the effect of a high sugar content would be. Could large organic molecules act as foci for gas bubble formation? Maybe a fun school experiment!

  • 3
    $\begingroup$ That second can had also just been shaken around for hours in your backpack. $\endgroup$
    – WBT
    Aug 27 '16 at 17:09
  • $\begingroup$ I'd conjecture that the separate instances of eruption from products bottled in different locations on different days implies that local conditions had the most impact. We're not far above sea level near Chicago - wouldn't see the same sort of low pressure that you had at 1.3 km. I do know from bottling home brewed beer that extra sugar results in more carbonation due to fermentation, but that's because conversion to alcohol produces gas. Doubt excess sugar in other beverages since most sodas are already so high in sugar. $\endgroup$
    – phil v
    Aug 28 '16 at 2:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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