Keg pressure keeps rising, what's going on?

Hi Guys,

I have a porter which I brewed a few months ago sitting in a cornelius keg. We recently moved and i've had no choice but to keep it at room temperature for about a month (about 25 degrees Celsius (77F)). It's been stored pressurised but not on gas supply.

It should be at approximately 2 bar (around 30PSI) at room temperature, When I checked it a few weeks ago using my CO2 regulator, it popped the safety blowout, it does this at 3 bar. I released the pressure and of course needed to do this a few times over the next few days to bring the gas levels down.

It's now a few weeks since then and I checked it again yesterday and it's up again to 2.5 bar.

What could be causing this? I didn't think there would be anything left to ferment to create the pressure. In a couple of days I will be able to put it in my kegerator (once i've finished it).

Do you think I will continue to have the same problem with it cooled down? what's the best way to manage reducing the pressure as it cools?

was this pressurized in a keg in a cool place prior to moving?

it was cooler but not refrigerated, it was stored in the basement of my old appartment building at approximately 18 degrees Celsius.

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.

BPS531 said:

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.

Click to expand...

Yes....

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.

DPB