Fermenting under pressure questions

[LemonJelly]

I'm in the process of fermenting a lager under pressure for the first time and had a few questions. I'm trying to keep it simple and straightforward as possible. I have my spunding valve set at 15psi and I plan on leaving it until final gravity. When transferring from my fermenting keg to my serving keg, I plan on attaching the spunding valve on serving keg set at 14 psi, for hopefully a nice slow, low foam transfer. Does my spunding technique seem right? Can I still cold crash before transferring? Or will this change the pressure in the fermenting keg?

 

[razzman]

Hi LJ. I’ve done a few pressure fermented brews now and I find that when chilling the finished beer the pressure doesn’t drop too much. My prv is a 20 psi valve and typically an ale ferment will be at approx 14 psi after chilling. I use a spunding valve, on the receiving keg, when kegging and set it by ear (if you know what I mean?) I open it until it just starts to allow gas to flow and leave it at that. Generally it takes about 20 minutes to fill the keg.
PS. Your method sounds okay.

 

[Gnomebrewer]

Chilling does change the pressure. My ales are typically about 25psi at room temp, get to 10psi once chilled, but it takes a few days. This chart helps
https://www.kegerators.com/carbonation-table/
You don't need a spunding valve for transfer. The method below saves CO2.
Have your serving keg at about the same pressure as your ferment keg. Use a length of beer line with a liquid disconnect on both ends, and another one with gas disconnects on both ends. Put the ferment keg on a bench with the serving keg on the floor below it - the bottom of the ferment keg needs to be higher than the top of the serving keg. Connect the gas disconnect line to both kegs, then disconnect it from the serving keg. Connect the liquid disconnect line to both kegs. Vent a small amount of CO2 from the PRV on the serving keg (just enough to start a flow from the ferment keg to the serving keg) then reconnect the Gas disconnect to the serving keg. The beer will continue to flow by siphoning. It takes a while to finish (maybe 20 minutes) but is easy and doesn't use bottled CO2!

 

[Vale71]

I'd still recommend proper lagering even for a warm-fermented lager. If you drop the temperature quickly and then trasnfer right away you will hardly experience any pressure drop as it will take a while for the beer to start absorbing CO2 from the headspace, whereas if you wait long enough pressure will drop and the beer will have increased carbonation.