Puzzled by kegged flat beer

[ASantiago]

Just got me a kegerator, but I'm new to kegging. I've read relevant posts and other information, including articles in Zymurgy and Brew Your Own. But I'm still... Puzzled by kegged flat beer.

The beer is cold. I'm keeping it at 42F or so (since before I kegged it). The CO2 tank has CO2 and I've been applying a constant 16 psi to two kegs in the kegerator. It's been a week. There is pressure at the taps and the beer comes out foamy. It's just that is isn't carbonated. At all. No little bubbles, not even for a few seconds (I'm using those Sam Adams' glasses with the lasered nucleation sites at the bottom).

The head sticks around, but I think it's more a function of the proteins and other things in the beer itself, rather than carbonation propping it up (it's a pumpkin ale and Kolsch).

What is going on? I haven't shaken the kegs, but that shouldn't be necessary if you give it enough time, shouldn't it?

Seriously, I'm stumped. Am I gonna have to get in the habit of dancing a dang tango with my kegs to get them to carbonate?

 

[Dan]

Give it another week at the 16 psi before you start worrying. I usually set the pressure on a cold keg to 30psi for about 1-1/2 to 2 days, close the CO2 valve, bleed off head pressure in the keg, open the co2 valve and adjust the regulator for about 10-12 psi. After another day or two the beer is carbed up well. It's a bit frustrating at first. Generaly, time will cure it.

 

[nebben]

I've heard that overcarbing a beer can sometimes produce similar carbonation as an undercarbed beer, at least in a draft system. The idea is that if a keg is overcarbed (or if the lines are too short/not enough resistance), the beer coming out will be so highly carbonated that all the gas in solution will want to get out. When being poured, a lot of gas comes out, and results in a lot of foam in the glass. Once this foam dissipates, the resulting beer is less carbonated than a properly carbonated beer.

YMMV.

 

[Airborneguy]

I agree with giving it more time (or increasing the psi). I'm not an expert in carbonation techniques - and keep my own simple - but I actually changed my routine from what you are doing because of the amount of time it took. I used to set mine at 17psi, and it took almost 2 weeks to have a decently-carbonated keg. I now set it at 25psi and shake the keg a bit whenever I get a chance. It takes about 3 days this way.

 

[ASantiago]

Great replies and certainly encouraging. Thanks!

I guess it will be like everything else in brewing: It will depend on your particular set up and the articles you read are either fairly general or very specific to the author's own experience and set up.

I'll go ahead and crank up the psi a little more and see what happens. It's my first kegged beer, so of course I'm anxious to see how it goes and, mainly, drink it! I didn't fight a super-stuck Pumpkin Ale mash for hours in the heat of the Orlando summer to drink the beer flat.

Regarding line length, I've read about the effect they can have. But my set up is primarily purchased, so I'm reluctant (at least right now) to do anything about the lines themselves. They seem a little long, but what do I know?

As far as shaking goes, I don't have a problem doing that, but the kegerator is so cramped, that I would have to take the kegs out in order to do that. My concern is the loss of temperature, although it doesn't seem we are talking about a lot time.

So, 25-30 psi for 2-3 days, shake on occasion, and dial down to 15-16 psi?

What about temperature? The kegerator will go to 32F and below, but I'm keeping the beer at 42F because the appropriate serving temp for many beers is that or higher. At what temp do you guys keep yours? (Temp affects the absorption of CO2 as well.)

Again, thanks!

 

[Airborneguy]

Once I'm carbed, I serve at 8-10 PSI. I'll only increase that if I'm having a few people over and know I'll be pouring frequently. At 8-10, I lose head/carbonation if I'm pouring beer after beer.

 

[ASantiago]

Once I'm carbed, I serve at 8-10 PSI. I'll only increase that if I'm having a few people over and know I'll be pouring frequently. At 8-10, I lose head/carbonation if I'm pouring beer after beer.

So, frequency of pouring affects carbonation, even with a constant psi applied?

 

[Bobby_M]

No it doesn't, not if you balance your lines. What Airborne is talking about is the process some people use where you drop your pressure down for pouring when your lines are too short. If you are sitting at 2.5 volumes after holding it at 14psi for 2 weeks, dropping the pressure down for serving will eventually lower the carbonation level over time.

16 psi at 42F will eventually get your beer to 2.75 volumes. This is a little high for most styles, but if you like it, that's fine. I'd be using 14psi for 2.5 volumes in most beers.

1. It takes more than a week to carbonate to the chart pressure by setting and forgetting. Wait another week and you'll be close.

2. After you get to carb chart carbonation levels, it's likely that your beer line length is too short to support pouring at 14-16psi. How long are the lines? It matters enough that you should measure them. Also make sure you note what the ID" is. If they are less than 8 feet, or if it is 1/4" ID and not 3/16" ID, buy some new tubing.

Whatever you do, no NOT shake those kegs.

 

[Airborneguy]

Like I said, I'm definitely no expert, but this has been my experience in my almost two years with my set-up. I serve on the low-end of the PSI range due to personal taste. I'm guessing that this low pressure level cannot replenish the CO2 fast enough if I'm pouring multiple beers, and frequently. This only happens at times when I'm pouring more often than usual. For my typical daily consumption, 8-10 is perfect.

 

[JuanMoore]

No it doesn't, not if you balance your lines. What Airborne is talking about is the process some people use where you drop your pressure down for pouring when your lines are too short. If you are sitting at 2.5 volumes after holding it at 14psi for 2 weeks, dropping the pressure down for serving will eventually lower the carbonation level over time.

16 psi at 42F will eventually get your beer to 2.75 volumes. This is a little high for most styles, but if you like it, that's fine. I'd be using 14psi for 2.5 volumes in most beers.

1. It takes more than a week to carbonate to the chart pressure by setting and forgetting. Wait another week and you'll be close.

2. After you get to carb chart carbonation levels, it's likely that your beer line length is too short to support pouring at 14-16psi. How long are the lines? It matters enough that you should measure them. Also make sure you note what the ID" is. If they are less than 8 feet, or if it is 1/4" ID and not 3/16" ID, buy some new tubing.

Whatever you do, no NOT shake those kegs.

This.

 

[Airborneguy]

No it doesn't, not if you balance your lines. What Airborne is talking about is the process some people use where you drop your pressure down for pouring when your lines are too short.

Now you have me wondering if I have an issue I didn't know about. I only have the problem I described when I pour like 4-5 beers one after another. I always figured it was because I have my serving pressure set so low. Are you saying it is something else? I've never had foaming issues so I always figured my lines were a good length. Should I look into that?

Take today for example, I'm by myself watching football, drinking maybe 1 beer per hour. I never have issues pouring at this frequency.

 

[JuanMoore]

Now you have me wondering if I have an issue I didn't know about. I only have the problem I described when I pour like 4-5 beers one after another. I always figured it was because I have my serving pressure set so low. Are you saying it is something else? I've never had foaming issues so I always figured my lines were a good length. Should I look into that?

Take today for example, I'm by myself watching football, drinking maybe 1 beer per hour. I never have issues pouring at this frequency.

If you're happy with it I guess there's really no problem. The carbonation level will always equalize with the headspace pressure, so the serving pressure should be set based on the desired carbonation and beer temp. You can then determine what beer line length will provide proper resistance to that pressure for a good pour. How did you determine your serving pressure and line length? If you chose the pressure based on what created a good pour, then your carb level is probably changing over time, but obviously not enough to bother you.

Could it be that the carbonation is actually the same between infrequent pours and consecutive pours, and it's just the level of head that's different? If that's the case it's probably because the faucet is slightly warm for the first pour, which knocks a little CO2 out of solution creating a nice thick head, but then cools off as more cold beer is run through it. That's the only logical explanation I can think of for what you're describing. I have a passthough tower, and even though I run a fan to keep the lines and faucets cool, the first pour of the hour always has more head than the subsequent ones.

 

[ASantiago]

Whatever you do, no NOT shake those kegs.

Do you mean in general or just now that the kegs have been under pressure for a while? It seems, again in general, shaking the keg is an acceptable and often recommended practice.

 

[subliminalurge]

Now you have me wondering if I have an issue I didn't know about. I only have the problem I described when I pour like 4-5 beers one after another. I always figured it was because I have my serving pressure set so low. Are you saying it is something else? I've never had foaming issues so I always figured my lines were a good length. Should I look into that?

Take today for example, I'm by myself watching football, drinking maybe 1 beer per hour. I never have issues pouring at this frequency.

If you have your system balanced, you can set your psi according to the co2 volumes you want, and be able to pour foam free glasses without ever adjusting pressure. Basically look at the charts for achieving certain volumes of co2 at different temperatures, then lengthen your 3/16" beer line until that pours with no foam. Also important to make sure the line is a constant temperature all the way from keg to faucet. A head on your beer should be a result of proper pouring technique, not just 'cuz the beer foams up when you pour.

I used to have a link to a chart that showed the correct line length for different psi and temperatures, but I can't find it right now. If I track it down I'll edit this post and add the link.

 

[Airborneguy]

Hate to steal this guy's thread, but it looks like I need to do a little work. Juan, I think you are dead on correct: my first beer has "good head" because the tap is warm. My set-up is a fridge, so the lines are completely contained within it with just the taps protruding from the door. I'm going to start adjusting my serving pressure in the next 2 days after carbing my most recent keg the way I have been doing it (just tapped a new keg now).

Subliminalurge, I think I have seen that chart. If it's the same one, it is the one that I interpreted to get my current method of carbing. I think my problem is that I then turn down to my low serving pressure, which causes the problem.

 

[subliminalurge]

Subliminalurge, I think I have seen that chart. If it's the same one, it is the one that I interpreted to get my current method of carbing. I think my problem is that I then turn down to my low serving pressure, which causes the problem.

Yeah, you really don't want to change the pressure any more than you have to. If you have the keg under high psi, then turn the regulator down, you've basically got the foaming already started before you even pull the tap.

Without a better description of the details of your setup, i'm not really sure what to tell you except for these two things: 1. You don't have to live like that. 2. Put in the effort to get it properly balanced and you will never regret it.

I've balanced systems for people who buy kegs of BMC, and they pour foam free and haven't had to even touch their regulator for years since I balanced their system.

Obviously homebrew is different since we're moving back and forth between different styles, but I'm telling you, there's no reason you have to be screwing with your regulator every time you pour a beer. At the most you should adjust every time you switch a keg. If it's really necessary to adjust psi when you pour, then your system needs a fix, and it's probably a really simple one.

 

[Airborneguy]

I don't change it every time I pour, just between new kegs. Basically, to carb a new keg, I set the PSI to 20. After a few days, I lower it back to 8-10. It stays there until one of my kegs kicks, at which time I repeat the process. But I definitely see your point. I'm going to try to get this fixed in the next few days once this new keg carbonates.

 

[subliminalurge]

Airborneguy, could you describe your keg setup?

 

[Bobby_M]

Do you mean in general or just now that the kegs have been under pressure for a while? It seems, again in general, shaking the keg is an acceptable and often recommended practice.

I guess there are differing opinions on this. You can shake the keg forever at that chart pressure and you'll never overcarb. It's just that a lot of people will crank the pressure to twice the chart pressure and shake to really push the process along. Anytime you boost the pressure, whether you shake or wait, you can overcarb. For folks that leave it at 30psi for 48 hours as a boost carb method, you're one distraction away from accidental 72 hours and then you're overcooked.

I hesitate to talk about how I do it because I'm not at the point where I'd recommend it to a new kegger. When the beer goes into the keg, I'll hit it with 50 psi, disconnect the gas, shake it and leave it overnight. Then I'll set the reg to the chart pressure and connect it.

The reason why this is a fool proof boost method is that a burst of 50psi into a headspace one tenth of the overall keg volume will quickly equalize down to a 5psi equilibrium. This means that if my target chart pressure is 10psi, it's already half carbed by morning. Technically you can burst it another 50psi in the morning, disconnect and shake again to get almost all the way there, but it's getting a little impatient at that point.

 

[Airborneguy]

Airborneguy, could you describe your keg setup?

I have a two-tap system installed in a one-zone upright fridge, Pin-lock kegs and Perlick taps. My CO2 tank is 20lbs. I use a single regulator with a split for the two kegs. Nothing fancy. It's Kegconnection's basic two tap set-up with upgraded taps and a bigger tank. I don't know how long my lines are off the top of my head, but they are whatever size Kegconnection provides (I never changed them).

 

[subliminalurge]

I don't know how long my lines are off the top of my head, but they are whatever size Kegconnection provides (I never changed them).

5 feet. I'd say that's almost definitely where your problem lies.

 

[Airborneguy]

So I need longer lines?

 

[subliminalurge]

It depends on a few factors. How carbed you like your beer, the temp you store it at, how high your taps are mounted.

The goal would be to use one of the carbonation charts and plug in your fridge temp and desired co2 volumes to get the pressure to set your keg at. Then add long enough line to balance against that pressure.

8 to 10 psi would probably get the beer a little flatter than I prefer it, but the calculator I just found says that 5 feet would be right in the ballpark for that pressure. When I plugged in the variables from my system it gave me 7.5 feet.

Then again, if you're storing the beer too cold it could even just be the sudden temperature change when it hits the glass that's causing the foaming.

I balanced one system for a buddy of mine quite a few years back. Not sure what the deal was, but ended up having to use 11 feet of line on it to get a good pour. (probably a crappy faucet, but I dunno...)

Here's a calculator that you could play with to get you some ballpark numbers. Just remember that each system is going to have its own quirks, so take that number as a guideline. You'll want to order longer line than it suggests so you have some room for a little trial and error to get it dialed in.

I'm certainly far from an expert, but I have done 4 or 5 for other people and always managed to get them pouring well, at the proper psi, by the time I was done.

EDIT: Oops, forgot to add the link for the calculator:
http://www.iancrockett.com/brewing/info/kegbalance.shtml

 

[JuanMoore]

The goal would be to use one of the carbonation charts and plug in your fridge temp and desired co2 volumes to get the pressure to set your keg at. Then add long enough line to balance against that pressure.

This.

And if you really want to reduce the difference in head between the first pour and pours right after, longer shanks will add thermal mass to keep the faucets colder.

 

[Airborneguy]

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

How's this one?

I'm using 8in shanks by the way.

 

[JuanMoore]

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

How's this one?

I'm using 8in shanks by the way.

That's the chart I use. I guess longer shanks won't really help any.:cross:

 

[subliminalurge]

Yeah, that chart looks good.

Just curious but what temp to you keep your fridge at?

As a homebrewer, I'll assume you know better, but when I've balanced systems for guys who just wanted to keep a keg of bud light on hand, it seems like they always have the temp cranked down to within half a degree of making beer slush....

I have my fridge set as warm as it'll go, and I still want to buy a temp controller since it's still too cold. Won't get warmer than about 37, and I'd like to see it more in the 42 range.

 

[Airborneguy]

I'm going to check the temp as soon as I go downstairs again. I'm thinking that may be a part of my problem. It's definitely not at its lowest setting, but I bet it is a little too cold.

 

[subliminalurge]

Best way to check it is to stick a thermometer in a glass of water and leave it in there overnight. The air temp will actually fluctuate up and down as the compressor goes on and off. The contents (including your beer, and the glass of water) will hold a pretty stable temp, though, and that's the temp we're really interested in.

A quick air temp reading won't hurt, though, it's at least a general idea of where the fridge is holding...

 

[Airborneguy]

Thanks for the little tips. I checked my temp with a thermometer (originally 36º) and stabilized it at 40º. So far, I have set my serving pressure at 15psi and seem to be doing much better. Poured a few beers pretty quickly yesterday (Father-in-law visiting), and had no issues. Im going to continue to monitor the set-up to see if I need to mess with my line length.

Thanks again!