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Safa · 10-02-2012, 02:08 AM

Thanks Bioguy, sounds good thanks, I'll do that.

BibB, the chart is only applicable when the gas is connected. Also, I'm not confusing terms, it is entirely possible, I was just unsure of the actual amounts of absorption of co2 into the liquid. If the kegs could hold what my scuba tanks hold, I could just throw 200 bar over the top of the liquid. Then the gas would be absorbed by the liquid until the ambient pressure of the head space and the gas in the liquid would be equal, hence equalisation. I don't have all the formulas at hand, but I bet we could pretty easily work out how many volumes of co2 would result from the method.

**BigB** · 10-02-2012, 02:29 AM

My point was that the `12 psi is an irrelevant consideration as it is temperature dependent. So, the 12 PSI is irrelevant compared to the volumes of C02 in solution...which is what you are aiming for when carbonating a beer. So if you are looking at disconnecting the gas after you have pressurized the tank to 45 psi, then who cares if it "equalizes at 12 psi" if the volumes of co2 are off. Now, I get what you are saying, kind of coming at the chart from a different direction by adding another variable. So it sounds like what you are really asking is if there is a chart or calculation for pressuring a vessel with a specific liquid at a specific pressure and a specific temperature that will result in a specific equalized pressure in a given period of time? Probably, but I'm not aware of one. You might want to send micromatic an email to their technical support... They might have something. Interesting question though, let us know what you come up with if you find something.

**Bobby_M** · 10-02-2012, 04:24 AM

Quote:

Originally Posted by Safa

Thanks Bioguy, sounds good thanks, I'll do that.

BibB, the chart is only applicable when the gas is connected. Also, I'm not confusing terms, it is entirely possible, I was just unsure of the actual amounts of absorption of co2 into the liquid. If the kegs could hold what my scuba tanks hold, I could just throw 200 bar over the top of the liquid. Then the gas would be absorbed by the liquid until the ambient pressure of the head space and the gas in the liquid would be equal, hence equalisation. I don't have all the formulas at hand, but I bet we could pretty easily work out how many volumes of co2 would result from the method.

I understand the question. It works out roughly proportional based on headspace volume to beer volume. In most kegs being filled initially, you'd have 5 gallons of beer and .5 gallons of headspace. Putting a single shot of 55 psi in the headspace will equalize across the 5.5 gallons to 5 psi.

Looking at the charts, you can tell that 5psi isn't quite going to do it at fridge temps, nevermind at room temp. It will get you closer than putting the keg in the fridge at 0 volumes however.

Safa · 10-02-2012, 12:18 PM

BigB: I'll let you know

BobbyM: how did you arrive at the 5 psi number? I'm interested! Because if that's the case, maybe all it takes is two or three refills! Which would totally work for me.

I know I'm lazy but taking my gas out of my fridge and putting it back each time I want beer will be a pain. Being able to switch the hose for a quick fill and then back to beer would be ideal, even if I have to do it two/three times over a few weeks.

**Bobby_M** · 10-02-2012, 05:19 PM

Based on Boyle's Law, if 55 psi of gas is allowed to expand to 11x the volume, it will be 1/11th the pressure. This batch burst method will either require that you prechill the beer or burst the headspace many times at room temp.

Using a max regulator pressure of 55 psi and room temp (70f) beer, the resulting volumes of co2 after each burst would be
.7, 1, 1.4, 1.6, 1.9

That same series with a beer temp of 40f goes like this
2, 2.3, 2.6, 2.9, 3.2
This assumes 5 gallons of beer in a 5.5 gallon container. Reducing the fill level to 4.5 will get you to 2.2 vols in just 3 bursts of 55psi at room temp.

Whattawort · 10-02-2012, 05:50 PM

Sorry if this has been mentioned before, but I honestly don't have time to sift through 60+ pages to find the answer. I have 5gal corney kegs, but this batch is only 3 gal. How much gas needs to sit on this or is does the amount of beer in the keg even matter? It's likely that this will be a common occurrence since I plan on bottling 2 gal/batch now.

jeepinjeepin · 10-02-2012, 05:55 PM

Quote:

Originally Posted by Whattawort

Sorry if this has been mentioned before, but I honestly don't have time to sift through 60+ pages to find the answer. I have 5gal corney kegs, but this batch is only 3 gal. How much gas needs to sit on this or is does the amount of beer in the keg even matter? It's likely that this will be a common occurrence since I plan on bottling 2 gal/batch now.

Same as a full keg. Make sure to purge off the oxygen well.

Whattawort · 10-02-2012, 05:57 PM

Quote:

Originally Posted by jeepinjeepin

Same as a full keg. Make sure to purge off the oxygen well.

Thank you much!

Safa · 10-02-2012, 06:09 PM

Quote:

Originally Posted by Bobby_M

Based on Boyle's Law, if 55 psi of gas is allowed to expand to 11x the volume, it will be 1/11th the pressure. This batch burst method will either require that you prechill the beer or burst the headspace many times at room temp.

Using a max regulator pressure of 55 psi and room temp (70f) beer, the resulting volumes of co2 after each burst would be
.7, 1, 1.4, 1.6, 1.9

That same series with a beer temp of 40f goes like this
2, 2.3, 2.6, 2.9, 3.2
This assumes 5 gallons of beer in a 5.5 gallon container. Reducing the fill level to 4.5 will get you to 2.2 vols in just 3 bursts of 55psi at room temp.

Thanks, that's perfect!

JDFlow · 10-15-2012, 04:40 AM

This is not a question but a realization I just had... I'll be kegging my first batch in about a week. I plan to cold crash while at work (about 10 hours) then rack to the keg. The realization: my beer will already be around 40 degrees so my kegerator won't have to work too hard to keep it cool and it'll be ready to carb as soon as it's racked!