Pressure in keg after chilling

[Mark_tries_brewing]

So I am new to brewing but started with a good bit of equipment. I think I dry hopped a little too soon. I didn't want to leave the beer on them for more than 7 days so I transferred to a keg (two nights ago) but I think my fermentation was not actually complete. I had a gravity reading of 1.020 but kegged anyway figuring it was because my temps in my mash spiked up to about 160-163 about 15 mins in (made a mistake and the water for the HERMS was too hot) and the recipe had an estimated fg of 1.018 anyway. Today my CO2 regulator arrived and before I hooked it up pressed down the poppet on the gas post to purge the air that had been in there. Despite having the keg in the fridge there was a burst of air coming out of the keg. I would assume from chilling the pressure inside would be below ambient but it was higher. A few minutes later I checked and more air rushed out. Is this an indication that the yeast (S04) is still working after 18 days, the last four of which were at about 40 degrees? Or is more likely its just some of the C02 left from fermentation coming out of solution? If I let the keg warm back up for a few days is there a chance it will carb naturally or should I just hook up C02?

 

[JeffD1]

So I am new to brewing but started with a good bit of equipment. I think I dry hopped a little too soon. I didn't want to leave the beer on them for more than 7 days so I transferred to a keg (two nights ago) but I think my fermentation was not actually complete. I had a gravity reading of 1.020 but kegged anyway figuring it was because my temps in my mash spiked up to about 160-163 about 15 mins in (made a mistake and the water for the HERMS was too hot) and the recipe had an estimated fg of 1.018 anyway. Today my CO2 regulator arrived and before I hooked it up pressed down the poppet on the gas post to purge the air that had been in there. Despite having the keg in the fridge there was a burst of air coming out of the keg. I would assume from chilling the pressure inside would be below ambient but it was higher. A few minutes later I checked and more air rushed out. Is this an indication that the yeast (S04) is still working after 18 days, the last four of which were at about 40 degrees? Or is more likely its just some of the C02 left from fermentation coming out of solution? If I let the keg warm back up for a few days is there a chance it will carb naturally or should I just hook up C02?

Admittedly I have no experience kegging, but from what you described it sounds like your fermentation was complete. 1.020 is definitely close enough to 1.018, and S04 is a very fast yeast. After 18 days, you should be good. Also, once you put it in the fridge, it will stop fermenting. My guess is what you said, that it was just CO2 coming out of solution. I would say add CO2, but I definitely have a limited knowledge of kegging.

 

[Mark_tries_brewing]

Additional question. If I had my regulator set to 14 psi and that pressure equalized in the keg and then turned the regulator down should it vent the additional pressure coming back into it? I was standing there and as I turned the pressure down it started to hiss. I was very confused and worried my regulator was broken (just got it in the mail today) so I turned off the tank valve. If I turn the pressure to higher than what is in the keg it stops hissing. Is it normal for the regulator to vent/ is there any problem with pressure (no beer in lines) coming back into it? Since I had already started this thread earlier in the evening figured I would ask, don't want to wake up to an empty tank.

 

[sandyeggoxj]

That is normal for a regulator to do. When you turn down the pressure from carbonating to serving pressure the best practice is to turn off the CO2 valve and then purge the pressure from the keg and then turn on the co2 at your serving pressure. If you serving pressure is high enough it will maintain an equilibrium of co2 in solution and keep the carbonation level throughout the life of the keg.

 

[Mark_tries_brewing]

At the time I didn't think about it but now, looking back there was a distinct popping noise as I turned down the pressure on the regulator. Checking it now it is definitely leaking. I have not tested with star san yet but it seems to be inside the body of the regulator. As far as I understand the tank gauge shows the pressure in the body of the main regulator. If I open the tank valve the gauge spikes and then if I turn it off I can hear hissing and the gauge quickly drops (this is with both check valve closed). Within a minute it reads zero. Also the needle on the regulator output gauge turns freely with the knob regardless of if the tank is on or the check/ ball valve on the output of the regulator is open.