I am currently fermenting a beer at 68 F under 10 psi. I do not have the ability to crash cool my fermentor when done. Will I need to de-gas this beer back down to atmospheric pressure before kegging? I have the ability to push the carbonated beer with CO2 and use my spunding valve on the receiving keg, but will it foam at 68 F?
Foaming occurs when CO2 comes out of solution. This is caused when pressure drops, temperature rises, splashing is created or a combination of the three. Keeping these conditions to a minimum will allow you to transfer without a foam problem.
I crash my beer to 40 degrees before transfer. and keep my Keezer at 36 degrees. Before transferring, I pressurize both the keg and fermenter to my set serving pressure. With CO2 connected to the gas side of the fermenter, a jumper between the liquid posts of the fermenter and keg and a picnic tap on the gas side of the keg, I release a bit of pressure by opening the picnic tap for a couple of seconds. A minute or 2 later, I again open the picnic tap again, and repeat as needed to maintain flow until all of the beer has been transferred. Once you’re certain the beer level is a above the bottom of the dip tube, you can increase the flow by releasing pressure more often with the picnic tap. With the lower temperature and filling the keg from the bottom, foam is kept to a minimum.
Even though your beer is at room temperature, you aren’t increasing the temperature, drastically decreasing the pressure or creating excessive turbulence as long as you start the transfer slowly and fill your keg from the bottom.
Note: You can use your spunding valve in place of the picnic tap and just lower the setting slightly below the fermenter pressure, but a picnic tap is faster and easier to control.
Just set the spunding valve on the receiving keg at 2-3 PSI lower than you’re pushing the beer at. It’s the pressure differential that leads to foaming. If the receiving keg is under a similar amount of pressure as the fermenting keg, then the CO2 will stay in solution and foaming will be kept to a minimum. Temperature isn’t an issue. I transfer from fermenting keg to serving keg at room temp as my standard practice. It just takes a while to transfer over, so be patient.
This has been my experience as well.
One additional tip: pressurize the receiving keg to your desired level before starting the transfer.
That helps, too. And you can kill two birds with one stone by filling the receiving keg with sanitizer first and pushing it out with CO2. This way you’re transferring to a purged, sanitized, and pressurized serving keg.
