Force-carbonated Homebrew Keg Foaming

Question

I see there are other keg-foaming questions on here, but they seem to usually be related to commercial kegs or have answers that I've tried (hastily).

I have a keg of homebrew brown ale and a brand new 2-tap Edgestar Kegerator which has a roughly 1ft tall stainless steel tower. We upgraded the hardware on the kegerator to have a manifold between the two CO2 lines as well as threaded disconnects to support either corny keg (ball lock) connectors or commercial kegs. The kegerator has been cold since Monday, and the keg was chilling for 24 hours on Monday/Tuesday in the kegerator before we started force carbonating it.

We are force-carbing it because we have a holiday party on Friday (tomorrow!) and we want to have it ready by then.

Finding various techniques for force-carbing, we ended up going with 20psi for one day and 30psi for another day, with rocking the keg every couple hours in between, before letting the CO2 out of the head space in the keg and getting it back down to 10psi.

We now have the liquid line connected, and nothing but foam is coming out, pint after pint. The beer itself, once the foam fades, is very flat.

Here's what other people have suggested to fix that I've already confirmed are not a problem:

• Get it cold - yep, the keg and the beer coming out of it are cold
• Use 3/16" ID tubing - it already came with that
• Make sure the lines are cold - they are, and the faucet itself gets cold once it starts flowing
• Make sure the lines are long enough - they are about 3', which according to the L = (P - (H x .5) - 1) / R formula they are more than long enough for 10psi
• Clean the lines - these are clean, brand-new lines
• Make sure the lines don't dip below the top of the keg - they're currently spooled up on top of the keg

Based on other answers and other websites, here's what I've tried:

• Setting the regulator to zero, clearing CO2 from keg, then slowing raising it back up - no luck at 5, 8, 10, or 12 psi
• Crank up the pressure to 10-12psi directly after clearing CO2 from keg - no luck

So is there anything I can do to get this ready for tomorrow evening? Is it undercarbonated (since it tastes flat) and the pressure is wrong for pushing it out, or is it overcarbonated and the flat taste is because of the foam? Do I really need to by a tower cooler fan to blow the cold air up into the tower? Or is there no hope for having it ready by tomorrow and we just need to let it sit at 10psi for 2 weeks?

Answer 1

If you completely purge the keg of CO2 and let it sit for 10minutes and the beer pushes itself out with the regulator shut off then the beer is potentially over carbonated. If the beer was overcarbed a simple burp of the keg and setting to 10PSI doesn't fix it. There is still CO2 that has to come out. Multiple burps and rests are required. A spunding valve helps in that case.

You should always start with longer beer lines than you think you need. You can always trim them back if the beer is over carbonating due to a higher than ideal serving pressure.

I think some of your math is wrong too, if when you calculated line length you rearranged this equation Pressure=length*resistance + 0.5Gravity.
It would rearrange to: (Pressure - 0.5G)/resistance=length

For most home based systems I have ignored the gravity piece. I use 2.2lbs of restriction per for 3/16th line. So at 3 feet you only have 6.6 lbs of restriction. At 10PSI that could be your problem. I have seen 3/16th quoted at 3lb/ft which then makes it closer to 10PSI. Here-in you can see why it makes sense to use longer lines and trim them later if necessary.

Lastly, make sure you don't have a kink in a line up in the tower. This can blindly be a source of foaming that no equation or line length is going to fix.

And yes, unless you want to waste the first 2 pints or so every pour... the lines in the tower need to be cooled. Or at least the lines very well insulated so once they are cool they stay cool during a serving session.

Answer 2

I force carb at 45 psi for 48 hours, if foamy, I turn the gas tap off and let the gas in the keg pump out the beer. You may have a leak between the keg poat and the beer tap or the beer out post might be letting a little air into the mix. Just a few ideas, I have a version of this problem sometimes but my beer will stay fizzy after the foam settles

Answer 3

Make sure the lines are long enough - they are about 3', which according to the L = (P - (H x .5) - 1) / R formula they are more than long enough for 10psi

3' is not long enough. There are a few different equations for that, but I've never ended up much less than 6-7' for a corny keg, and some equations get you closer to 10. I switched from ~3' to 6' recently and it made a huge difference, especially after about 3 weeks, where in my setup (always 10psi) they would start to get super foamy.

However, this isn't going to make your beer flat, just foamy. It sounds like the CO2 is not in solution. (Need more time, more pressure, more rocking...)

Answer 4

There is good advice in the other answers, but I would like to add one more solution: Perlick forward sealing flow control faucets

I bought these for my kegerator because I got tired of the rear-sealing faucets I had gumming up over time, and I found the flow control faucets on sale for the same price as the standard ones. I recently used them with a couple of commercial kegs, and they worked great with adjusting the flow to make the initially foamy beer pour better.

Answer 5

Check your regulator, make sure it's actually reading "PSI". I've seen some people try to use welding co2 regulators, which are in Liters Per Minute "LPM", and are flow regulators not pressure.