Beer pouring foamy out of serving tanks

[NYSBrewer]

I have recently started using serving tanks in our pub. The first two batches to come off of them poured like a dream for the first half of the batch. Once the level of beer got below half way, the beer started pour foamy. Anyone know a way to prevent this? Are there any quick fixes once it begins to happen? My top pressure is around 12 psi.

[BMOOR]

straight CO2? If you have a blend box for a N2 mix, I don't have an answer. If it is just CO2, you may have overcarbonated your beer.

[Fred Scheer]

What are the size of your serving tanks? Is the resitant time of your beer
in the tanks to long; i.e., you are not selling the beer fast enough, the beer will absorb to much CO2 and start foaming.
I recommend to keep your room temperature where the tanks are located at 34*F, the pressure on the tanks ~ 10 PSI, which gives you ~ 2.58 CO2 vol in the beer.
If the beer is over carbonated, release the pressure daily (slowly) early in the morning (b4 your pub opens), and before the doors of the pub open, hook up the CO2 again.

Hope this helps,

Fred :)

[NYSBrewer]

Size of tanks are 7 bbl. I am pushing with straight co2. The beer has been in the tank for 4 weeks. We have been waiting on a liquor license for that long. We got the license a week ago and the tank has almost been emptied in that time. My carbonation level was 2.47 last week before we began service. It has dropped below the sample valve now so I can't check it at this point. What I dont get is why the beer started out pouring fine for the first half of the batch. Could it have overcarbonated due to head space in one week? The beer is almost gone anyway, but I want to avoid this in the future. My cold room is set at 36 degrees. I do have a few lines that run from kegs, and I push those with a beer gas mix. Should I be pushing my serving tanks with that too? Problem is my co2 lines for the serving tanks come from a bulk tank that carbonates our sodas as well.

[RobZamites]

Seriousely, invest in a McDantim blender and push with mixed gas. I carbed in 7 bbls tanks to 2.3 volumes and the beer ran great to the last drop with a 70/30 CO2/N blend.

[NYSBrewer]

How much do they cost, no pricing on the website.....

[scott isham]

How long are the tap lines? I don't think you can make an educated answer on how to push your beer without that info. The problem with mixed gas is that most serving tanks only can take 15psi and your already have 12 psi now, so it won't really make a difference

[BMOOR]

The mixer Rob speaks of is probably 400-600 I think and it will save you tons in the long run if you are not pouring foam down the drain. And, I'll bet a nitrogen tank is less expensive than a mixed gas tank. maybe? Also, the mixed gas would be better on the serving tanks than the kegs because the gas has a longer contact time with the beer in a tank. When you have a bbl of beer left in the serving tank, you have 6 bbls of gas sitting on top. You'll have a hard time getting it to pour well if it is just CO2. Finally, concerning the soda, you can branch off anywhere from your bulk. Just "T" off the bulk line that heads to the soda-run that to the blend box. Put the N2 tank right under the blend box and you have mixed gas. Easy to install yourself and hopefully your problem is solved.

[NYSBrewer]

Tap Lines are long, 80-100 feet. Thanks for all the answers, if anyone has any more info, I would love to hear.

[jarviw]

what is the BEER temperature in the serving tank?
with any pouring issues, check your temperatures first!

Like others said, it is possible you do not have your tank pressure set at the equilibrium with respect to CO2 level and temperature, and you are over carbonating the beer over time.

But the first thing I would check is the beer temp in the tank (not just the cooler temp!) It is possible your tank temp is higher than what it should be, which will require higher head pressure to keep the CO2 stay in beer
and therefore over-foams during pouring.


What I didn't get is, do you have 80-100' beer line from serving tank to the tap too? and you are using 12 psi to push it?

[Beersmith]

Dispensing a 2.4v of CO2 content beer at 36F and 100% CO2 will ultimately overcarbonate at anything above 9.1 PSI. A blender would definitely improve your situation. I believe a McDantim 2-blend Trumix 200 runs about $750 or so. It is much cheaper to buy separate nitrogen and CO2 bottles and use a blender than using pre-mixed gas - better results too. Most of the major draft equipment companies (Micromatic, Perlick, etc) carry McDantim blenders. Some local beer distributors can also sell them. The blend can be pre-set to match the requirements of your draft system: you will need to know the temperature at which your beer is stored in the serving tanks, the average original CO2 volume content of the beer, and the amount of line restriction you have to the faucets. Roughly speaking, a 2.4v CO2 beer at 36F would necessitate a blend of about 75% CO2/25% Nitrogen. You won't regret installing one - ours has been going 9 years now and not a single problem. Thousands and thousands of beer dollars saved!

[scott isham]

For lines that long you're going to need beer pumps. I don't think your tanks will handle the pressure needed to push beer 80 feet. I have about 100 ft lines and I use beer pumps and have about 12 psi on my servers

[Moonlight]

Is it possible that when there is a problem, it is when the beer is below the cooling jackets in the tank? If so, it doesn't matter what a randomly-placed thermometer on the tank reads, nor if the cooling jacket is on full-time, because if the beer isn't touching the jacket, it is going to get warmer. Insulation and cladding only slows this inevitability.

[Beersmith]

Moonlight brought up a very good point. If your tanks are only rated to 15 PSI and the length/restriction of your lines is great enough, it may require a dispense pressure of mixed gas greater than 15PSI to pour properly. And we all know that we never want to exceed the tank's rated pressure...... In that case, beer pumps are probably the only way to go. The draft equipment companies have technical reps that can help you determine what equipment you need based on your draft system.

[Beersmith]

Just correcting myself, Scott Isham made the point about beer pumps...

[scott isham]

I was just thinking about this some more. It may be possible to use 1/2 inch or 3/8 inch line until about the last three or four feet then switch it to 3/16ths. 1/2 and 3/8 inch lines have very little restriction, that being said, I think beer pumps are the best way to go. But first as someone else said I would make sure of the temps and head pressure are not creeping around.

[NYSBrewer]

Wow! When you guys get going this gets fun! Ok, yes 100 ft lines, no beer pumps, as far as I know, they never used them before., my tanks are rated for 20 psi, so maybey it is just a simple fix of pouring at a higher pressure. alot of bars in my area have long lines, and no one uses pumps. The tanks are not jacketed. Since we just opened, a $750 price tag is a bit steep right now. I talked with a local draft tech, and he suggested I try a beer gas mix instead of the pricey blender for now. Should I still pour at a higher pressure with the mix? Say 18 psi? Thanks for all the responses, you guys are great. I anyone is EVER in the syracuse area, pints are on me! (as long as they are not foaming!)












]o

[scott isham]

Do this first. Pour a beer that you're having trouble with and measure the temperature. How are your lines being cooled? It may be a simple fix of beer warming slightly in your lines.

[NYSBrewer]

Lines are cooled with a brand new glycol trunk line system. All lines go through the same trunk, so if it was a temp prob, they all would be foaming.

[scott isham]

If all your beers come out of the tap at about the same temp,(and close to the temp of the serving tank) that eliminates the temp issue, and the focus should be on pressure.

[BMOOR]

I may not go up to 18 PSI, but do try increasing the pressure. (however this will continue to carbonate your beer) MAny people think that the solution to foamy beer is to turn off the pressure becasue there is too much. Instead, once the CO2 is in solution, you have to increase the pressure to keep it in solution.
When I have to hurry a beer on that is not fully carbonated (pulled into a keg from the fermentor, I have to force carbonate it. SOmetimes I over do it and it just takes a little increase of the kegs gas line to get it to pour nicely.

If you feel like your temp is good in both the tank and in the lines and you can get a mix gas on the tank so it won't over carbonate by the end, then just tweak up your serving pressure and see if it works.
Another option is lower your co2 volumes in the beer. We run 2.2-2.3 That might be a little low, but if you are going to keep pushing with CO2, you will find your beer gaining CO2 probably. Starting at 2.4 means you will have overcarbonated beer sooner.

finally, I also like the idea of changing the serving line size. If you talk to a draft specialist, they can calculate exactly how much line and what size you need for your pressure and temp.
Good Luck

[Beersmith]

NYSBrewer,

After looking at all your info, here's what I would do to start with to (hopefully) get your draft system pouring right with minimal upfront costs. This assumes that you have no temperature issues at the faucet.

1. Run whatever brand of pre-mixed (CO2/N2) gas that is available to you. It will mostly likely be in the 75% CO2/25% N2 range.

2. Set the dispense pressure at about 18PSI. That will keep your beer close to CO2 equilibrium in the servers at the stated 2.4v initial CO2 content and 38F.

3. Once the system and tanks are all up to pressure, test pour a pint. The general rule is you want to pour a pint of beer in 8 seconds. You can adjust the pressure either way to get close to an 8 second pour.

4. Monitor how your beers perform (carbonation levels) over time in the serving tank.

If your draft system pours well, and the beers maintain desired carbonation levels over time then all is well. Although, getting a blender will definitely save you money over time in gas purchases.

If the beer does not maintain desired CO2 levels, then you should definitely get a blender or go the beer pump route. Installing a blender that is pre-tuned for the specfics of your draft system makes a huge difference. Either McDantim or Micromatic can help you select the proper gas blend to use.

You may need to add some additional restriction in your beer lines if you are having to dispense at high mixed-gas pressures. A few feet of 3/16" ID beer line immediately before the shanks will usually do the trick. Obviously with your servers, you are going to to limit dispense pressure to 20PSI.

In the long run, a properly tuned draft system will save you THOUSANDS of dollars annually. It is worth spending the money to make sure it works properly. Not to mention that your customers and employees will also be much happier with system that pours a perfect pint.....

[jarviw]

larger beer lines also mean more beer sitting in the beer lines -- more waste during line cleaning! and I generally don't like the idea of having ANY beer sitting in between the serving vessel and the glass, glycol cooled or not.

just fyi,
1/4" ID line holds 1/3 oz/ft
5/16" ID line holds 1/2 oz/ft
3/8" ID line holds 3/4 oz/ft

multiply by the length, that's how much beer you will be washing off every two weeks per line.

There are times you absolutely need to use larger ID lines, but I will go with that the very last. Try beer pump or mixed gas first!

[scott isham]

You are going to have to base the head pressure on the amount of restriction in your lines as well. 100 feet of 3/8 barrier tubing which is probably what you have is going to have resriction of 6psi. 4 feet of 3/16 will give another 12psi, so if you have 18 pounds of head pressure, that will balnce out and should pour well.

[NYSBrewer]

Thanks alot guys, I'll keep you all posted as to what happens, right now just racked a 2.33 volume beer into a serving tank, got mixed gas on it at 18 psi.....fingers are crossed, I'm gonna have the "big guy" look at this thread and see if he wants to look into a gas blender.

[beauxman]

Go for the blender, you will pay for it quickly with reduced loss of beer (assuming everything else is balanced/ok). You would be amazed at how much beer you waste with foamy taps and impatient bartenders (it should be fast and easy to pour beer, not a chore). Try this, unhook your tap tower drain tray from going to the sewer and let it collect in a five gallon bucket. Empty and record often. Add up the amount lost for one week and figure out how much money that would have been in a pint glass instead of in the slop bucket. This is real money. It sounds like you are on the right track, it really is a simple equation of temp, pressure, restriction and balance but can be very frustrating nailing it down. Great thread with lots of input....gotta love it!
-Beaux

[edramshaw]

NYSBrewer,

Be sure your gas company supplied you with a 75% CO2 / 25% Nitrogen mix and not the other way around as is common for pouring nitrogenated beers like Guiness. If they did you will have flat beer in a few days because you are really only sitting 4.5 lbs of CO2 on top of the product. Good luck.

Ed
Blue Line Draft Systems, LLC

[beauxman]

If I am not wrong (and I could be), pressure is pressure. If you have enough pressure holding the CO2 in equilibrium then your volumes of CO2 are going to be stable (assuming temperature doesn't change). Nitrogen is much harder to get into solution and at dispense pressure won't even really get there. The beauty of using nitrogen mixes is that at a given pressure it is harder to get into liquid than CO2, hence why it is used to keep the volumes in line at a given PSI. I forget the science but it has something to do with partial pressures of the gases...forgive me Steve Parkes, it's been a few years and more than a few beers!
-Beaux

[edramshaw]

Pressure is pressure but equilibrium will be reached based on the mix that is sitting on the beer. If you have only 4.5 (25% of 18) psi of co2 on your beer then after a few days you will end up with 1.85 volumes of co2 dissolved into it. You are right about nitrogen but it is more so used to push a product (at least in my experience). The beauty is that you can put 24 lbs of blended gas (40N/60CO2) on a beer and push it to where it needs to be with only 14 lbs of co2 affecting the beer. Since nitrogen will not readily absorb into the beer it makes an ideal mixing gas. Either way you want the beer to come out of the faucet tasting the way you brewed it and dispensing plays a huge role in that. As beersmith pointed out, you will save thousands by doing it right the first time.

Ed
Blue Line Draft Systems, LLC

[jarviw]

Beaux>

Ed is right about the partial pressure in the mixed gas system. The gas blend ratio is absolutely critical at the given temp/carbonation - hence the customization flexibility for the blenders!

N2 pressure will not keep CO2 in solution (at least not in the macro sense), only CO2 pressure can do that.

the 70:30 CO2/N2 blend is really designed for dispensing beer at 38F, which you may or may not want to serve your beer at that temperature.

McDantim has a gas blend calculator at

http://www.mcdantim.com/calculate2.htm