do I need to completely disassemble forward-sealing Perlick taps to clean them?

I am still fighting the foam in my system. I have 10' of 3/16" ID beer line which should be enough at 38 F to not allow CO2 to come out of solution. I am getting 1/4 glass of foam and 3/4 glass of beer. Watching the beer come out of the faucets, I notice 1 or 2 "pulses" of foam come out, followed by clear beer. So I think it's only spitting foam for part of the pour. I was wondering if dirty lines, faucets, or keg posts could cause CO2 to come out of solution in a Venturi-like effect.

When I switch kegs I just run 5 gal of PBW through, then 5 gal of StarSan and assume it is clean after that much exposure. I don't disassemble all the parts and soak them individually. I assumed this is whats commercial bars are doing, or do they have to break down their system between kegs? I have the Perlick 525 chrome taps, and I though the forward-sealing feature kept it clean in between pours.

My first thought is that part of your beer line is warming up. Are you using a mini-fridge style of kegerator with a tap? Or perhaps a keezer with a collar and not much air circulation? Does this happen on every pour or the same tap, or only on the first one after several hours?

Is the issue significantly worse on the first pour of every drinking session, and then better if you pour another beer quickly? If so, then the beer is either carbed higher than whatever corresponds to your serving pressure, or the lines/faucet/shank are getting too warm.

Dirty lines or faucets can also cause this, but they have to be really really crusty. And bars do remove the faucets and take everything apart, but they do it every few weeks instead of after each keg. They also pour a lot more beer than we do, and tend to have worse sanitation practices, so we don't need to clean ours as often.

latium said:

My first thought is that part of your beer line is warming up. Are you using a mini-fridge style of kegerator with a tap? Or perhaps a keezer with a collar and not much air circulation? Does this happen on every pour or the same tap, or only on the first one after several hours?

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I have a converted side-by-side fridge with kegs in the freezer side. The lines are fully enclosed at the same temperature of the kegs, until it flows through the actual taps. I used to have the fridge outside during the summer and I think that caused even more foaming. Now it is in the garage where it's closer to 45 F right now and I'm still getting too much foam so it's not a temperature issue

JuanMoore said:

Is the issue significantly worse on the first pour of every drinking session, and then better if you pour another beer quickly? If so, then the beer is either carbed higher than whatever corresponds to your serving pressure, or the lines/faucet/shank are getting too warm.

Dirty lines or faucets can also cause this, but they have to be really really crusty. And bars do remove the faucets and take everything apart, but they do it every few weeks instead of after each keg. They also pour a lot more beer than we do, and tend to have worse sanitation practices, so we don't need to clean ours as often.

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I'd say it is worst the first beer, and only marginally better if I pour another one right away.

I can actually see the foam pulsing out in a couple glugs, so I don't think it is continuous foam, and like I said I get 3/4 of a glass of beer. With 10' lines, I wouldn't expect to be undercarbed at the outlet side. I pressurize the kegs to 10 psi. I have gone as high as 14 psi and tried line lengths from 5' to 8' to 10' to eliminate the problem

I also saw a video on here where someone was showing a poorly-manufactured liquid quick disconnect causing a Venturi expansion. I guess I could buy another QD and see if that fixes it.

One note - sounds like you're going a little overboard on cleaning, and probably wasting a lot of CO2 as a result. All I do to clean my lines each time is to fill up a small (maybe 1qt?) bottle with warm Beer Line Cleaner (BLC) solution and run that through my line, then run probably a half gallon of warm rinse water through the line. And that's it. Maybe every other cleaning I'll break down the faucet completely and give it an overnight soak in OxiClean Free or PBW. But to run 10 gallons of fluid through the lines and tap must use up a good amount of CO2, unless you've got a way to hook up an air compressor to your set up instead.

As to the foaming, a little more detail could help. Do you get that foam every time you pour, or only on the first pour off of a given tap (well, the first time within a reasonable period - say the first time within 15 minutes or so)? Also, you mentioned your line length and temperature, but I didn't see a pressure - what pressure are you serving at?

EDIT: I just saw your answers on the pressure and frequency of foaming... It's almost starting to sound like you're getting air in your beer line somehow - the "glugs" sound really suspicious to me. Maybe the venturi expansion idea. Another thought is how is your beer line connected to your quick disconnect? Is it a barb fitting, or is it an MFL and swivel nut connection? If a swivel nut connection, maybe you need a gasket in there and/or some additonal teflon tape? If it's a barb, or if you've already got the gasket and the teflon tape covered, then you may be on the right track trying a new disconnect.

What's your serving pressure? You don't need anymore than 5 psi to pour beer. (Considering that there's enough pressure on your beer)

VincentK said:

What's your serving pressure? You don't need anymore than 5 psi to pour beer. (Considering that there's enough pressure on your beer)

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Not necessarily great advice here... You carb up your beer at 10psi, then drop it down to 5psi to serve, and over time your beer will off gas to achieve equilbrium with the reduced pressure in the headspace in the keg. Best case, you get flatter beer over time. Worst case, your beer is just a little too close to your gas dip tube and you wind up with beer backed up into your gas lines.

VincentK said:

What's your serving pressure? You don't need anymore than 5 psi to pour beer. (Considering that there's enough pressure on your beer)

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Yeah that's terrible advice, sorry. If you're backing off the pressure to serve, you're introducing a ton of new potential problems (losing carb, foaming, etc). If you turn it up then purge and bring it down every time you grab a beer, you're also going to waste a whole lot of CO2. Much easier to balance the system, use a carb chart/calculator, set it and forget it.

OP, it sounds like the faucet probably isn't the problem. Check the dip tube o-rings on your beer "out" fitting, that's a common place where gas can get injected into the beer line. And flare fittings (aka swivel nuts / MFL) should never get PTFE tape. If it's a metal on metal contact you do need a nylon washer.

VincentK said:

What's your serving pressure? You don't need anymore than 5 psi to pour beer. (Considering that there's enough pressure on your beer)

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That's exactly how to cause this issue, not fix it. If the serving pressure is lower than the pressure that corresponds to the carbonation, CO2 will come out of solution in the lines forming pockets of gas, which will cause the first pour to be extra foamy. Not only that, but as the keg empties it will also become undercarbonated as it reaches equilibrium with the new lower serving pressure.

zachattack said:

Check the dip tube o-rings on your beer "out" fitting, that's a common place where gas can get injected into the beer line.

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Another good suggestion.

One last possibility is a manufacturing defect in the shank. In some longer shanks the internal hole is drilled from both sides, and there have been a few cases where the holes weren't lined up properly, creating a sharp lip and restriction in the middle of the shank that can create foaming.

Well I carb my beer quickly around 40 degrees at about 30psi for give or take a day then lower to 3-6psi and serve and I get perfectly carbonated beer with minimal foaming if any... Like they say, ask 10 brewers 1 question and you'll get 12 different answers. Just play around with serving temp and pressure and you should find what works for you and your particular beer.

It's not really a matter of opinion. If you drop your pressure lower than your desired carbonation level equilibrium pressure in order to pour without foam, it will begin to lose co2 and continue until it hits the new pressure. You can keep bouncing the pressure back and forth, but I'd rather go back to bottling than play that game.

VincentK said:

Just play around with serving temp and pressure and you should find what works for you and your particular beer.

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And let your beer quality suffer? Pick a serving temp, and let the style (and/or your preference) pick the volumes of CO2. Then calculate the pressure, and leave it there till the keg's kicked. If you can't serve it properly, adjust your system accordingly. I don't understand people that go to all the trouble to make their own beer and then can't put a little effort into balancing lines or keeping temperature consistent.

If you're keeping your beer at 3-6 PSI at 40 deg F, after you've pulled a few pints it's going to equilibrate at 1.6-1.8 volumes of CO2 unless you're pumping the pressure back up each time. And that's basically flat for most (American) beer styles. Not to mention you'll get significant foaming until it all balances out.

I know that I have a pulse of foam on the first beer and is fine just after the pulse and I can get a perfect pour. I use 10 feet of 3/16 beer line and keep the kegs at 12 psi or what ever pressure that I need to keep it at the proper level. I have even had it up to 20 psi when I was force carbing and didnt get a lot of foam and a good beer just the right amount of head. I am also using a keezer with a collar so all the lines and shanks are kept cold.

sorry just got back from work and I'll try to catch up with all the comments here

1. not going to adjust the pressure specifically for serving. set-it-and-forget-it for me. Once I get this thing balanced, I'm not going to touch it. I'll just pick a happy-medium carb level and not try to rebalance for each style

2. so even though my fridge is set to 38 F, I measured a fresh pint with my calibrated AccuRite thermometer and got closer to 43 F, so is this the true temperature to use for calculation? I don't like drinking beer any colder than that, but if it's preventing me from balancing the system, I can go down to 36 or 38 and just let the pint warm up before I drink it.

3. glad to here a complete teardown is not necessary for the faucet between kegs. For those who only push a gallon of cleaning solution, how do you connect it to the kegging system? Are you just pouring it into an unpressurized system with a funnel or something? Can I substitute PBW for BLC? I'd like to avoid having to keep a third chemical in my cleaning inventory.

4. The lines are connected on both ends via barb fitting. I had to heat the ends in hot water and jam them on to get them over the barb. After cooling down and contracting, there is 0% chance of air infiltrating at the barb fitting. In fact I have to cut off the end of the line when I adjust the length because I can't pull it off.

I clean my lines with an empty keg when I have the cleaner in there I just hook it up and run it through the lines then I put star san in there and run a a quart in the keg and satitize the keg then I hook it to the tap and run all of it out until I jest get co2 out of the tan and close it and leave the pressure in the line until I am ready to use it. as far as the temp I do use the temp af a fresh poured glass to set my pressure level.

It sounds like what one other forum member said... air getting in your lines/loose connections. I had this happen when my out post on my keg wasn't totally tightened down after cleaning. It wouldn't leak beer or CO2 (!?), but on the pour I got tons of foam and I noticed my lines would slowly get a larger and larger air bubble in them between pours.

The mis-manufactured shank is a good thought, too.

I use one of these when I clean my lines. Bascially, I unhook the faucet, hook this up in it's place, fill the bottle up with cleaner solution, then hook up the QD to an empty keg and hand pump the cleaner through the lines. Then repeat with rinse water. I suppose you could do this with PBW or OxiClean, but BLC is damn cheap - $13.99 for 16oz of it, and if I'm not mistaken you use 1/2oz per cleaning, so it lasts damn near forever.

If you want to go the opposite direction, and save a few bucks, do some searching around the forum and you'll find someone has figured out how to put a specific ball lock post onto a cheap chemical sprayer bottle you can pick up at home depot, so you can fill that bottle up instead, and pump from the QD end and out through your faucet.

the temperature of the faucet is not the problem - garage is cold so it's not warming up between pours. Pouring two beers back-to-back gives the same amount of head

all other things being equal, should a lower temperature give less foam @ psi?

twd000 said:

[...]all other things being equal, should a lower temperature give less foam @ psi?

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Yes, just as surely as warmer temperature causes more foam.

Beer is carbonated to a certain level dependent on temperature and pressure. Once the carbonation level has stabilized, if you take that beer and raise its temperature, it can't hold as much CO2, so gas will escape invariably causing foam to form. Otoh, if you took the same beer and lowered its temperature, it could actually hold even more CO2, so you've removed one factor for gas breakout...

Cheers!