Commercial Beer CO2 Volumes and Balancing System

[PunkIwishIwere]

I just bought a keg of Boston Lager and tried to find a listing of the CO2 volumes of commercial beers but couldn't find anything. Being a lager I made the assumption that it was about 2.5. Obviously, I need the correct volumes to get the system balanced. I emailed Sam Adams, but they have not responded yet. Has anyone come across such a chart/list?

With the assumption that there were 2.5 volumes and I wanted the beer at 38 F, my calculations gave me a regulator pressure of ~11 psi. My faucets are 2.5' from the center of the keg and I'm using 3/16" tubing. So, if the volumes were correct I would need 3.33' of tubing. I got everything hooked up and I got nothing but foam at that 11 psi. Also, after letting it just set for a while I noticed that the regulator crept up to 13-14 psi. I assume this means the keg is actually closer to 2.7 psi??? Does anyone have experience with this particular beer?

If I have ever over carbonated a beer, I could just bleed the head pressure to reduce the volumes. I'm not so familiar with this sanke coupler, but it appears that the relief valve only takes pressure directly from the gas line. Is there a way I can bleed the pressure or is dispensing at a low pressure and letting the beer naturally out gas the only way?

Recap of my questions:
Is there such a list that shows commercial beer CO2 volumes?
Does anyone have experience with this particular beer?
If possible, what is the best way for me to lower the volumes of the beer?
How do you guys balance commercial keg systems without knowing the volumes? (I know the easiest way for me to do this is to experiment with longer to shorter hose lengths, but I only have 4' 8" of tubing left and it's a huge pain in the ass to change everything...of course no pants would make it a ton easier.)

If you actually made it this far, thank you for any advise or criticism for being so stupid!

[Mylo]

I have found that those charts are guidelines at best. Most commercial kegerators that you can buy that have the tower on top of the fridge (about 2 feet above the center of the keg) - come with at least 5 feet of 3/16" tubing. When I first bought mine, I had a keg of "normally carbonated" commercial beer (ie. 2.5 vols) that I tried to serve at 38. 11 PSI also resulted in a glass full of foam.

The best thing to do is to make sure everything is clean and cold. Beerline has to be cold up to the faucet - so use a squirrel cage blower and some 1" tubing (Micromatic sells both). Make sure the beer is stable at the desired serving temp and pressure. Then start with a longer than necessary length of tubing, and keep cutting off 2-4 inch lengths until you get the desired pour rate from your faucet. I like no more than 2 oz/sec.


Mylo

[bcmaui]

Sounds like your tubing is too short. Where you have a little over 3', I am using almost 7' of 3/16" line at a similar temp and pressure.

[PunkIwishIwere]

Mylo, did you mean the lists of commercial beer volumes or charts/equations for balancing are just guidelines?
I used the equations from this site: http://hbd.org/clubs/franklin/public_ht ... lance.html that were then plugged into an excel spreadsheet that another guy gave me. I've double checked it and it all makes sense to me.

I guess the next stop is to make the like excessively long and keep hacking down from there. That means a lot of beer will be sacrificed in the name of science and I'm getting drunk tonight.

Oh, one more thing. I've noticed that I'm getting bubbles escaping from the keg into the beer line. I looked it up and I gather that this means my applied gas pressure is less than what is in the keg. Correct?

Thanks guys.

[bcmaui]

Bubbling in the hose has also indicated a leak at the post gasket for me in the past. Even with the longer lines I am using, I still got foaming in that instance. I pushed it all over to another cleaned keg, reconnected the lines and all was fine. That first keg now has all new gaskets.

[bcmaui]

Just remember this was mentioned in another thread and you may find it handy:

http://www.draughtquality.org/

[Mylo]

Oh, one more thing. I've noticed that I'm getting bubbles escaping from the keg into the beer line. I looked it up and I gather that this means my applied gas pressure is less than what is in the keg. Correct?

Yes, or a leak - as Bill mentioned.

and yes, I was talking about the calculators that are on the Internet to help you determine the appropriate tubing length for your particular setup.


Mylo

[PunkIwishIwere]

BC, I enjoyed that pdf but I don't think it helped me much. It just helped to confirm that I have no idea what is going on with this system.

I am 99% sure that the fridge/beer is at 38 F because that's what two calibrated thermometers in a glass of water read. I came to the conclusion that the volumes were more than 2.5 (~2.7). So, I set my regulator to 13psi and the bubbles in the beer line have basically stopped.

Then, I started again with 8' of line to see how that went. At the moment I have to pour out a pint or more until the foaming stops before I get a good 2oz/second pour. I'm almost convinced this foaming is because the tower is not cooled, yet. Although that's only one foot of line inside the tower with the other 7' sitting inside the fridge at presumably ~38 F.

Now my confusion still comes from the resistance estimations. Again, I'm using 3/16" tubing and I've used a somewhat conservative value of 2.5 psi per foot (most equations I've seen use 2.7-3.0). Using my value, I still come up with about only 5' of line needed. These equations have always worked for my homebrew so I still find it hard to believe that the lengths could be almost 3' off.

Thanks again for the great responses.