Originally Posted by BPS531
Cold liquids can hold more dissolved gas than warm ones. As the beer warms up, it will release CO2 until the head space pressure is so high that the amount of gas leaving the liquid is the same as that going back into the liquid. If your head space was small, there could be multiple iterations of that happening as you release the pressure.
On the other hand, higher temps could have restarted fermentation, either with yeast and residual sugar or some sort of infection.
Think shaking a warm soda and opening it... waaaa-oooosh.
If you chill it it should reabsorbe the CO2...
When I transfer beer from a Keg to a Growler I always chill the beer, the Growler, and the tubes that will be touching the beer. Sso when the cold beer hits the gowler it does not release its CO2; If it does;;;; when I getwhere I am going the beer maybe flat.