I've built a very efficient foam machine

[Imix500]

Hello all,

First thread for me. I have read a dozen or so threads about excess foam but I have had no luck even with all the great advice. I had trouble with the pre-built generic Kegerator dispensing all foam so I lengthened the beer line.
Here's the setup-

Keg at 42°F
Beer (foam) in glass 44.4°F
Regulator at 12PSI
15' 3/16 line

Any ideas?

Thanks!

 

[zachattack]

All foam? Is this a commercial keg or a corny keg?

 

[b-boy]

If it's a Corny keg it sounds like you're overcarbonated. Did you force carbonate? Add sugar? Use the shake method?

If it's a commercial keg, you can turn down the serving pressure. I think 12 may be too high. I'd shoot for ~5-6 PSI.

 

[zeptrey]

Maybe your beer is a little too warm. Get it below 42 degrees if you can. Also, make sure everything is super clean and then sanitized.

 

[masonsjax]

Your temp and pressure should be adequate. Did you mess with the regulator (just recently set it to 12psi) or has it been carbed by setting it to 12psi and leaving it? If you blasted it with higher pressure or shook it to get carbed up, you're almost certainly over carbonated. Purge the lid a few times per day over the next few days to get it to settle and in the future just leave it at serving pressure until it's ready.

If it's not over carbed this could be a temperature stratification issue, the lines and/or faucet are warmer/colder than the beer, causing co2 to come out of solution. Make sure the line is coiled up neatly, not touching the sides of the fridge and put a small fan in there to keep the air temp even throughout.

There could also be some turbulence causing the foam. Check for kinks in the line, beer stone deposits, scratches, maybe you have extra couplings or connectors in the path, or possibly defective disconnects? Make sure the poppet valves are clean and that post o-rings are intact.

 

[hunter_le five]

LOL at the thread title.

I agree with the others. Temp/pressure/line length/etc specs that you've listed all seem okay, which suggests over-carbonation as a likely culprit. What was your carbonation method?

 

[evanmars]

Also, make sure you open your faucet all the way. Don't try to 'slow the pour' by only opening the faucet a little.

 

[Heavywalker]

knowing your carbonation method would be helpful.

 

[Imix500]

Thanks for the replies!

The line is coiled neatly and neither it or the keg is touching the sides of the unit. It is a corny keg.

So, as this is my first keg I was unaware you could be over-carbed and still have correct pressure at the regulator. I figured the beer would out gas and equalize the head space at the over-carbed pressure. Science!

Carb method was originally sugar primed but I had a gas side leak that I think negated that. I did not notice the leak for about a week.
I then forced it overnight at 25psi. Dropped it to 12 after 24 hours and it's been about a week since then.

I will drop the temp to 38 in the mean time.

Thanks!

 

[GilSwillBasementBrews]

Did you bleed off the excess gas in the keg when you dropped it to serving PSI? If not your beer will hold the over carbed pressure in the headspace until you release it by pouring a glass of foam until the pressure drops below what regulator is set for. You want to use the PRV in the lid of the corny with your regulator set to serving pressure Turned off. Bleed excess gas from headspace of keg. Then open the valve on the Co2 bottle( after closing Pressure Release Valve )


Sent from somewhere to someone

 

[Imix500]

I reduced pressure by pouring a couple glasses of foam. I have pin lock so no manual valve unfortunately.
So, if I need to bleed some gas from the keg, do I shut off the reg, bleed gas from the gas side connector, then turn the reg back on or do I let it sit for a bit before turning the reg back on?

 

[DrunkleJon]

Looks like you are dialled in pretty well for serving homebrew.

The foam that is pouring. Is it just the first pour and subsequent ones work fine, then after a while its foamy again? Or are all pours pure foam?
Looking at your beer lines, are bubbles forming in the lines from the tap end, middle, or keg end or no bubbles in it whatsoever?
Are you using a cobra/party tap or the shank and faucet style? if faucet, is it cool or warm to the touch?

Commercial kegs tend to be carbonated at higher carbonation volumes than homebrew typically is. I find that slowly increasing serving pressure until you stop seeing bubbles form at the keg coupler into the beer lines is the best fix for that unless beer is coming out of the tap very fast.
If bubbles are forming mid beer line or forming at the tap area, you probably have temperature stratification issues, a small fan in your beer foam machine should help this. You can also tell this is the problem if using metal faucets and they are warm to the touch.

 

[Imix500]

Hi,

The pour and subsequent pours is all foam. A very fine foam that takes a good 5 min to settle.

It's a tower/shank/faucet deal. Just the cheaper one that came with it.

The faucet isn't warm but it's not cold either. I'd say a bit cooler than room temp. After a pour it cools down further of course.

Thanks,

 

[j1n]

Id take the gas off of the keg since its likely over carbed. Then release the gas from keg via the pressure valve every so often. then lower the serving pressure to 10 psi and check the beer.

 

[BPO]

Here is a great article that was posted on home brew finds.
http://www.homebrewfinds.com/2014/06/balancing-your-draft-system-three.html
When I over carbonate here are the steps I use to fix the issue.
1. Remove co2 gas line
2. Bleed pressure off of gas side.
3. Pour beer/ foam(with gas side still off)
4. If it still foams bleed more gas off. If the gas bleeds off slow, you can shake the keg and then bleed of gas.
5. Repeat step 3 and 4 until you get a glass of beer and not foam.
Usually when this happens I will leave the gas off. I don’t turn the gas back on until the beer is flowing correct for a few pints.

 

[DrunkleJon]

Sounds more and more like overcarbonation. Turn off gas, purge headspace every couple hours for a day or two. Turn gas back on, and enjoy. Heck dispense beer/foam too while you are purging. May as well get some beers out of it. Tell SWMBO that drinking the beers is to fix the system. See if it flies.

 

[Imix500]

Hello all,

Well I decided to follow the article BPO posted and bled some gas before work. I bled quite a bit- probably 15 secs or so. I poured a bit just out if curiosity and it was already much better! I'll let it sit today with the gas off and check it tonight.
Hopefully we are headed in the right direction.

Thanks!

 

[Imix500]

Hello all,

Well I decided to follow the article BPO posted and bled some gas before work. I bled quite a bit- probably 15 secs or so. I poured a bit just out of curiosity and it was already much better! I'll let it sit today with the gas off and check it tonight.
Hopefully we are headed in the right direction.

Thanks!

 

[Takuie]

Another way to decarb over carbed beer, I prefer this method as it doesn't require me to pour more foam out.

1 - Unhook gas line.
2 - Shake/rock keg for about 20 seconds. (Shake it hard, the harder the better)
3 - Burp keg
4 - Repeat steps 2 and 3 until a little bit of foam comes out relief valve (usually 3-4 times)
5 - wait about an hour and burp keg again
6 - reattach gas line and set to 1/2 of serving pressure. Wait about 2 hours and try another pour.

Rinse and repeat as desired.

Once carb level is good, return pressure back to normal.

 

[WileECoyote]

Id take the gas off of the keg since its likely over carbed. Then release the gas from keg via the pressure valve every so often. then lower the serving pressure to 10 psi and check the beer.

+1 , enough said!

Cheers

 

[masonsjax]

Note that lowering the temperature may slow down the process of fixing over carbonation problems. CO2 dissolves easier into beer the colder it is so it will be less likely to off gas when colder. I'd leave everything be, just disconnect the gas line and purge a few times a day for a couple of days. Then hook it back up at serving pressure and you should be good to go.

 

[BPO]

With the shaking and bleeding of the gas pressure you can fix the beer in just a few minutes. It is good to remember if you take too much carbonation out you can add it back just as easily, by force carbonation. I agree with DrunkleJon. A long term study should be done with many test samples.

 

[Imix500]

Here here for the test samples!

So, I did another purge tonight and it had a surprising amount of pressure again. Funny how that works!

I did try a few sips and it had a very upfront CO2 bite, so obviously we are not there yet. I'll continue for another day and see where it lands.
Do I judge if enough out gassing has occurred by how the beer tastes?
When I'm happy with the carbonation I'm done?
Seems like a very scientific way to determine it!

 

[Imix500]

I am actually very curious about the science though. Trying to understand how more gas can be dissolved when the headspace pressure is less? Or is the headspace pressure not less? Going by the regulator gauge here- it should reflect the headspace pressure correct?

 

[JuanMoore]

Here here for the test samples!

So, I did another purge tonight and it had a surprising amount of pressure again. Funny how that works!

I did try a few sips and it had a very upfront CO2 bite, so obviously we are not there yet. I'll continue for another day and see where it lands.
Do I judge if enough out gassing has occurred by how the beer tastes?
When I'm happy with the carbonation I'm done?
Seems like a very scientific way to determine it!

You'll likely need to purge it many times over the course of at least a day to get the carb level down noticeably. Sitting with the gas disconnected doesn't reduce the carb level at all, you need to give somewhere for the excess gas to go. And yes, just keep purging until it tastes like the carb level you want.

I am actually very curious about the science though. Trying to understand how more gas can be dissolved when the headspace pressure is less? Or is the headspace pressure not less? Going by the regulator gauge here- it should reflect the headspace pressure correct?

The carb level can be higher than the corresponding pressure in the headspace right after you've vented the keg, but gas will come out of the beer and it will build back up to equilibrium pressure within a few hours. The headspace pressure and carb level will always reach equilibrium with each other eventually.

If you have a properly functioning check valve in the gas system somewhere (which you should) then the regulator gauge will only read the pressure in the keg up to the set pressure of the regulator, but not higher. So no, in many cases your gauge does not reflect headspace pressure.

 

[DrunkleJon]

Exactly. The beer which is carbonated highly has a lot of dissolved CO2. When you vent pressure it takes a little while for the CO2 to come out of solution and build pressure in the small headspace of your (mostly full) keg. Once pressure of headspace CO2 matches that of the dissolved CO2 it is in equilibrium and no more comes out. If your keg were half filled, more would come out of solution after each venting and it would go far faster (since more CO2 would have to come out of solution to fill and pressurize the headspace).

 

[Imix500]

Hello all,

So a couple weeks later I am still chasing a correct pour. (Note that I travel a lot so there has been much inactivity with the keg)

I believe I have let enough gas come out of solution as I can release pressure in the morning and have just have 4 seconds or so of relase 8 hours or so later. Not a very scientific measurement I know.
I still have a lot of foam though. It's a different type of foam now- much larger bubbles that settle much faster but still leave little carbonation in the beer. There is a little in the beer now, but most is going to foam.
Do I need to wait a bit after turning on gas to serving pressure (now about 10psi) before serving?

Thanks!

 

[GilSwillBasementBrews]

No you should be able to leave it at serving pressure. There isn't anything good to come of constantly changing your PSI to the keg. I have 10' lines and run my regulator at 12-14PSI at 38F and leave it set there constantly on. Usually will take 1.5-2 weeks to have fully carbed beer.


Sent from somewhere to someone

 

[DrunkleJon]

Agreed. Once you have uncarbonated it enough, put it back on serving pressure (I leave mine at around 12psi) and let it sit. You should be able to pour without all the foam so long as the serving pressure is equal or exceeding the current carbonation level (so long as you have enough restriction in the lines to slow your pour down).

 

[Imix500]

Hello all,
So I gave it a day at 12psi and it's still all foam. What is my best next step? Maybe I underestimated how much CO2 had to come out, but I'm not sure.

Thanks!