Foam!!!!

Hi, I have just tried doing my first kegged brew. I carbed it by chuckin 30psi down the outlet valve (corny keg), shook it until it stopped gurgling, and then a little while longer. Left that over night, then released the pressure by pushing the inlet/gas valve. I have now got it pressurised to about 4 or 5 psi for dispensing. I am using a peice of tube with an inside diameter of 6mm to the tap. I have had it resting all day, but when i pour a glass, I get a glass full of foam, seriously, from top to bottom. I have tried pouring a number of glasses, thinking it may just need to be purged out or something, but after 10+ glasses, I still get foam. If I let it settle in the glass I'll get a half glass eventually, but thats not ideal. Is there something I'm doing wrong? does it matter where the tap is positioned on the fridge door in relation to the keg? (it's only just under the height of the keg top). Is the 6mm tube all good? Or am I just being impatient and should leave it to settle overnight and see how it goes tomorrow? cheers.

There's a few things you're doing wrong, but the main one is that you probably severely overcarbonated your beer. What was the beer temp when you did the shake at 30psi, and what was the temp as it sat overnight? If it was cold, it only takes a minute of shaking at 30 psi to carbonate fully, and it's very easy to overdo it. Even if you only carbed it half way by shaking, letting it sit overnight at 30psi would probably get it the rest of the way there.

The second issue is the serving pressure, which needs to correspond to your carbonation level. If you set the serving pressure lower than the carb level, the gas will want to come out of solution to reach equilibrium, which will creats pockets of gas in the lines, and make for foamy pours. At 4-5 psi, even at very cold serving temps that equates to only ~2.0 vol of carbonation, which is obviously lower than what you carbed it to by shaking it at 30psi.

The last issue is line balancing. You need the lines to provide enough resistance to counter the serving pressure so that the flow is slowed to a manageable rate and doesn't create a firehose of foam. The 1/4" (6mm) ID line provides very little resistance, and is used mostly in long draw systems for bars where the beer has a long way to travel. To get enough resistance you'll need either very long 6mm ID lines, or 5-10' long 3/16" ID lines (~4.7mm). How long is your serving line?

If your beer is indeed overcarbed, which will be hard to tell until you get the system properly balanced, you'll need to vent the keg many many many times over the course of a few days to get it back down to where it needs to be. Here's a handy chart for determining pressure based on desired carbonation and beer temperature-

http://www.kegerators.com/carbonation-table.php

The temp I had it at during the shake and settling has been 4 degrees C (39.2 F). The serving line is 2m long (6.5 Foot). It certainly sounds as though I've over done it. Does the gas line have any affect on it? as that is quite large - 8 or 10mm ID. So from what you are saying, is it ideal to have the serving pressure similar to the carbing pressure? Is it better to carb it at a lower pressure over a longer time? cheers

Peeow said:

The temp I had it at during the shake and settling has been 4 degrees C (39.2 F). The serving line is 2m long (6.5 Foot). It certainly sounds as though I've over done it. Does the gas line have any affect on it? as that is quite large - 8 or 10mm ID. So from what you are saying, is it ideal to have the serving pressure similar to the carbing pressure? Is it better to carb it at a lower pressure over a longer time? cheers

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The size and length of the gas line has no effect on carbonation. Regardless of how you carbonate, the serving pressure has to be in equilibrium with the carbonation level. If you carbonate your beer to 2.5 vol, but then serve it at 4psi and 4°C, the carbonation level will drop every time you pour a beer until it reaches equilibrium at 1.77 vol. Likewise, if you carb a beer to 2.0 vol, but then serve it at 12psi and 4°C, the carbonation will increase over the period of a few days until it reaches equilibrium at 2.52 vol. Use the chart I linked to determine what serving pressure you need to use to be in equilibrium with your carbonation level. Once you know what your serving pressure is, you can then figure out what length and diameter beer line you need to have a balanced system and a good pour.

There are a lot of opinions on the "best" method to carbonate beer. One thing I can say is that the faster you try to do it, the greater the chances are that you'll end up with a carbonation level other than what you wanted. I usually use the "set and forget" method, which takes about 2 weeks. Most of my beers could benefit from the extra conditioning time, and since I usually have a decent pipeline going I'm rarely in a hurry. It's a little harder to be patient when it's your first keg. In the rare cases that I am in a hurry, I chill the keg to serving temp (which for me is 39°F/4°C), and then set the pressure to 30 psi for ~36 hrs (no shaking). Then I purge the excess pressure from the keg, and reset it to serving pressure (2.4 vol is what I like for most of my beers, which means 11psi @ 4°C). After another day or two at serving pressure it's usually reached full carbonation.

I highly suggest reading the sticky about kegging at the top of this forum. Lots of good info in there.

I find the best thing for me to do it get it chilled down to the proper temp (40 F). Once that is done I check he chart and select my psi (usually 10-12 psi). Then take it out of fridge put the co2 on it and rock it back and forth for 30-45 min. Then once that it done put it in the fridge on gas and let it cool back down again wait 1-2 hours and it's perfect but for me, I have to run a 10 foot line at 3/16 and no foam and it's perfect.

Putting it under 30 psi and doing that would be only for soda because the volume of co2 is soo high. If you over carbonated like i did once, I take the keg out of the fridge and off gas, release the pressure and carefully shake it to relase co2. Then relase pressure again. you may get foam coming out but usually you be carefully of that. Keep doing that till it is just about flat and then start over again at the proper psi level. Once you have the proper psi keep it there for serving.

Thanks for the advice. I am currently getting it flat againand gonna start over with the advice given. Just one more question though, that I havn't found an answer for in the forum. Does it make any difference wether you gas it through the outlet valve as opposed to the inlet valve? I was just following the directions of another noob, and that is what e recommended. From my understanding it wouldn't really make any difference would it? if the CO2 is going to be absorbed by the fluid while under pressure, it would do it from the top or bottom, yes? And it would be a pain disconnecting the gas line and attaching it to the beer disconnect everytime I was carbing...

Peeow said:

Thanks for the advice. I am currently getting it flat againand gonna start over with the advice given. Just one more question though, that I havn't found an answer for in the forum. Does it make any difference wether you gas it through the outlet valve as opposed to the inlet valve? I was just following the directions of another noob, and that is what e recommended. From my understanding it wouldn't really make any difference would it? if the CO2 is going to be absorbed by the fluid while under pressure, it would do it from the top or bottom, yes? And it would be a pain disconnecting the gas line and attaching it to the beer disconnect everytime I was carbing...

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Many people mistakenly believe that by letting the gas bubble up through the beer, the increased surface area in contact let's the CO2 absorb faster, and it carbonates the beer faster. For that to work the gas bubbles need to be broken apart into thousands of tiny bubbles, such as with an airstone. Without an airstone it really doesn't make any difference which post you push the gas through to carbonate it. I'd suggest using the gas post to avoid the hassle of swapping hoses as you mentioned.

Ya it don't make any difference. If you put the keg on its side and roll it back and forth, the beer goes up the side of the keg and thins out allowing more surface area to absorb the gas. Just be careful and make sure the gas line is on the top so the beer don't go back into your gas line destroying the regulator.

So I am having some trouble as well. I have probably overcarbed my beer, and when I pour I am getting all foam as well. The difference being, I am getting very little carbonation out of the liquid that does pour. It's practically flat with a bunch of foam.

EDIT: This is my first time kegging.

sweaterman said:

So I am having some trouble as well. I have probably overcarbed my beer, and when I pour I am getting all foam as well. The difference being, I am getting very little carbonation out of the liquid that does pour. It's practically flat with a bunch of foam.

EDIT: This is my first time kegging.

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I know this sounds crazy, but it's flat because it's overcarbed.

Why this happens is the crazy foaming causes the co2 in suspension in the beer to get knocked out in the foam, so the beer is flat but the foam is heavy.

A couple of things to fix this. One is to take the beer off of the gas and pull the pressure relief valve often.

A few other things that may or may not be making it worse that you can check- make sure your serving lines are longer than 6'. I started with 6', went to 8' and am finally foam-free in all pours with 10'. The second thing is to make sure your beer is cold. Warm beer foams worse than cold beer.

Thanks Yooper, I suppose there is no chance I can release enough CO2 by this afternoon, right? From what I have seen it takes a couple days? I have a friends party I wanted to bring it to this afternoon. Screwed the pooch on this one. Nuts.

sweaterman said:

Thanks Yooper, I suppose there is no chance I can release enough CO2 by this afternoon, right? From what I have seen it takes a couple days? I have a friends party I wanted to bring it to this afternoon. Screwed the pooch on this one. Nuts.

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There is a way to to release the excess gas almost instantly, but there's a good chance that it would release too much gas, and you'd end up with flat beer instead of overcarbonated beer. Put your gas line on a liquid disconnect, and turn the pressure down to 4-5psi. Connect it to the liquid out post, and pull the pressure relief valve for 20-30 seconds while letting the gas bubble up through the beer. You might get some foam coming out of the pressure relief valve. The agitation from the large bubbles will knock a lot of the gas out of solution.

yep, I found the same with mine.

JuanMoore said:

Put your gas line on a liquid disconnect, and turn the pressure down to 4-5psi. Connect it to the liquid out post, and pull the pressure relief valve for 20-30 seconds while letting the gas bubble up through the beer. You might get some foam coming out of the pressure relief valve. The agitation from the large bubbles will knock a lot of the gas out of solution.

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To clarify, are you just saying hook up my line from the CO2 to the liquid out post (but prior to this, hooking the correct pin lock up to the co2) and running low psi through it with the release valve open?

Bugger! I've got another drama! Finished mowin the lawns, poured a beer and ........foam!!! I had it sweet, it was at 12 PSI and all was good. I have a secondary digital regulator inline with the gas line, my primary reg is actually a flow reg, so I can't read PSI on it, hence the reason I've got the digi one in line. Anyway, I checked the pressure and it had creeped up to 25 psi!!!! so now I'm over carbed again. I isolated the gas line from the keg and confirmed that the 25 psi was actually coming through the primary reg, but it has been untouched. Could I put this down to a **** reg? does the temperature inside the fridge affect the reg? I have now adjusted the secondary reg to 12 PSI as a back up, so I'll keep an eye on that. But now I'm back to square one with trying to get the beer flat on a hot sunny Saturday afternoon, just when I really wanted a beer or 6