Keg Conditioning

[doug293cz]

Update: The keg that was sitting around 22psi at 65° in my closet (see #18 above)View attachment 838114was moved into the utility storage room and is reading 14-½ psi at 45°, sitting BESIDE my cooler; not in it!
That puts me right at 2.5 volumes, which is admittedly at the top end of the range for an Irish Stout, but definitely acceptable. I used the full 5oz. (by weight) for the 5 gallon batch.

I should get a number of good pours out of this using a Tapit 2.0 before hooking up to CO2. The bonus is that at this temperature, which is what I have my cooler set at, there’s no need to lift it over into the cooler; I can just use it where it sits.
Cheers!

Another data point that says keg carbing requires the same amount of priming sugar as bottle carbing.

Brew on

 

[DuncB]

Surely this data suggests that the beer has not reached equilibrium yet with the higher pressure reading. Should it not equilibrate to the same vols as before it was cooled ( given enough time ).
Unless it was still fermenting.
Also what was the target vols with the added sugar expected to be?

 

[mac_1103]

Surely this data suggests that the beer has not reached equilibrium yet with the higher pressure reading. Should it not equilibrate to the same vols as before it was cooled ( given enough time ).
Unless it was still fermenting.
Also what was the target vols with the added sugar expected to be?

22 psi at 65F is 2.1 volumes and 15 PSI @45F is 2.5 volumes. I'm not sure how precise @Closet Fermenter's temperature measurements are. But I don't think the beer should equillibrate to the same volumes since CO2 is more soluble in liquid at lower temperatures. IOW, CO2 moves from headspace to beer as temperature drops, which is why the headspace pressure drops, right?

 

[VikeMan]

IOW, CO2 moves from headspace to beer as temperature drops, which is why the headspace pressure drops, right?

There are a few interactive things going on. The solubility of CO2 in the beer increases as temperature drops, causing some net movement of CO2 from the headspace to the beer, decreasing the headspace pressure a little. And as the beer volume decreases, due to temperature decrease, the headspace increases, which also decreases the headspace pressure a little. But a big reason for the drop in headspace pressure is that gases are simply at lower pressures when they are at lower temperatures, because the gases are less energetic . (PV=nRT)

 

[Closet Fermenter]

22 psi at 65F is 2.1 volumes and 15 PSI @45F is 2.5 volumes. I'm not sure how precise @Closet Fermenter's temperature measurements are. But I don't think the beer should equillibrate to the same volumes since CO2 is more soluble in liquid at lower temperatures. IOW, CO2 moves from headspace to beer as temperature drops, which is why the headspace pressure drops, right?

The temperature measurements were not precise. In the warmer location, I left it several weeks until it stabilized. If you look at the picture in #18, you can also see the needle has passed the scale on the gauge; so again, an estimate.
After leaving it in the cooler location for awhile, the needle dropped back into the readable scale, and I used the temperature from a temperature strip on a carboy next to it; they were exposed to the same conditions and I assumed that they had reached the same equilibrium temperature. Neither precise nor accurate enough for science, but close enough for me and my brew; alas, it is beer!

 

[Bramling Cross]

Back in the olden days I used to carbonate my kegs with table sugar at kegging time. After a few days I’d pop it in the fridge overnight and tap it the following day.

I’m not one of those guys that argues that we can’t really be sure how steam beer got its name.

Oh, I know. Believe me, I know.

 

[Closet Fermenter]

I typically find my initial pressure a little higher than serving pressure, but by using a PT 2.0, I can “harvest” this extra CO2 and dispense a fair number of pours before connecting to the tank. I will admit that I may not be as particular about carbonation levels as some might be; I am ok within a range, so your preferences will determine how much you may pour before you feel the need to connect to the tank.
I will say, my tank has lasted a LOT longer after purging with fermentation gas, keg-carbing with sugar, and dispensing with the carbonation pressure.

This is my fourth pour from the naturally carbonated keg, full 5oz. corn sugar. This time, I didn’t vent the keg and hook up to gas, but just put a Tapit 2.0 on the keg and began pouring. The 15psi put it right at the top of the useable range of the tap. Admittedly, the first couple were a little foamy, but they went down the hatch just the same. With the fourth poor, the pressure dropped below 10psi, so I connected the gas line. I’m in business; not even in the cooler. Looking forward to moving up to a larger batch in my half barrel sanke!