Cider Wraith
Well-Known Member
Looks like the Vols to PSI @ temp charts are intended as guidance on carbonating still beverage. For example, in a five gal corny at room temp with one to two gals headspace over still beverage, if tank pressurizing to about 30 PSI, after a being chilled a couple of days, CO2 will have been absorbed into solution and pressure will drop into single digits. So, headspace pressure over still beverage can drop by more than two-thirds given time and temperature. Multiple things are going on, liquid and headspace volume, temperature, time and I appreciate CO2 will move into or out of solution over temperature, time to achieve stasis.
Next, with similar conditions, if pressure fermenting the beverage will have already absorbed maximum CO2 at given pressure, temperature, time. So if pressure fermenting to about 18 PSI observation seems after being chilled headspace pressure drop is slight, maybe only a few PSI to around 12 ~ 14. Seems to make sense given that the beverage is already saturated with CO2, the difference being only the change necessary for equilibrium at the new temperature. If so, then seems one could simply pressure ferment to a few PSI over serving?
If what's described above seems correct, do charts or formulas exist that show headspace pressure change based upon temperature change alone in sealed systems at equilibrium?
You folks would have described this far better, maybe the above assumptions are all wrong. Feedback / words of wisdom appreciated
Next, with similar conditions, if pressure fermenting the beverage will have already absorbed maximum CO2 at given pressure, temperature, time. So if pressure fermenting to about 18 PSI observation seems after being chilled headspace pressure drop is slight, maybe only a few PSI to around 12 ~ 14. Seems to make sense given that the beverage is already saturated with CO2, the difference being only the change necessary for equilibrium at the new temperature. If so, then seems one could simply pressure ferment to a few PSI over serving?
If what's described above seems correct, do charts or formulas exist that show headspace pressure change based upon temperature change alone in sealed systems at equilibrium?
You folks would have described this far better, maybe the above assumptions are all wrong. Feedback / words of wisdom appreciated
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