Foamy kegged beer

[nexy_sm]

Hi all guys,

last week I tried for the first time to keg my beer into sankey kegs.

My setup is calculated to have pouring speed of about 10s/pint. I have 4mm beer line ... I put my beer on initial 30 psi and didn;t shake anything. After two days when tapping it, I realized that pressure dropped and that beer was quite flat. So I put it again on 30psi, shaked the hell out of it and put it one day to stay in the fridge. Them, I vented my keg and put it on serving pressure which is 0.95bar (probably about 13 psi). However, the beer was foaming and pouring out pretty fast. It wasn't overcarbonated, but rather undercarbonated. What I realized is that initially when I open the faucet, a lot of foam bursts out.

Any suggestion how to fix this.

Cheers

 

[JONNYROTTEN]

First you need to read up on force carbing and line balancing.
Flat foamy beer is co2 breakout. The co2 "leaves" the beer and creates foam.
Get good beer lines they make a difference
Get a Perlick flow control tap and forget about all your issues.It'll be your best kegging investment

 

[nexy_sm]

Hi,

ok but my beer line is about twice as longer as suggested by line calculator. If I understand things correctly with long beer line and appropriate serving pressure there should be no foaming at all.

 

[JONNYROTTEN]

Hi,

ok but my beer line is about twice as longer as suggested by line calculator. If I understand things correctly with long beer line and appropriate serving pressure there should be no foaming at all.

So whats the actual line length and what did the psi drop to? Your best bet at this point is purge, set to serving pressure and wait a few days for it to balance out. You could be over carbed. The shaking second time around and leaving on 30 psi might have overdone it.

 

[nexy_sm]

My line is 2m long and 4mm radius. Serving pressure was 14 psi. One could see bubles insige beer line.

 

[MagicMatt]

There are several problems here it seems.....

I put my beer on initial 30 psi and didn;t shake anything. After two days when tapping it, I realized that pressure dropped and that beer was quite flat. So I put it again on 30psi, shaked the hell out of it and put it one day to stay in the fridge.

It sounds like you didn't leave the gas connected? Otherwise how could you "put it again on 30psi" if you never removed it? When carbing a keg, the best method is to set it to your desired carb level based on the temperature of keg, and leave it there for 2 weeks. If you want to "burst carb" the keg, you need to leave the 30psi on the keg for at least 24 hours, likely closer to 36 hours (and that's at about 32°F/0°C). All it seems you did is push the keg to 30psi and then disconnect the gas. The beer will absorb all of that CO2, but it isn't much at all, and thus you still had flat beer.

Then, you put it on 30psi and shook it. This was your second mistake. You never want to shake the keg while attached to gas unless the gas is set to the serving pressure. Otherwise, you risk overcarbing the beer. Essentially you instantly carbed it to the full 30psi (depending on how long you shook it, but it doesn't take too long). What you should have done was put it on 13psi and shake - there is no chance to over carb that way.

To me is seems your beer is now overcarbonated. Then there's the issue with line length:

My line is 2m long and 4mm radius. Serving pressure was 14 psi. One could see bubles insige beer line.

2m is NOT long enough. Bubbles coming out of solution means that there isn't enough resistance to keep it in suspension (i.e. lines are too short). I don't know which calculator you're using, but you say you doubled what it suggested - this would mean a suggested length of 1m, which will give you nothing but foam with a serving pressure of 14psi at serving temps.

This is the only line length calculator worth using, and I'm confident that if you plug your numbers into the calculator you'll see a suggested length of closer to 4m.

 

[nexy_sm]

Hi,

MagicMatt, thank you for you generous answer. However I would like to ask some additional questions.

There are several problems here it seems.....
Then, you put it on 30psi and shook it. This was your second mistake. You never want to shake the keg while attached to gas unless the gas is set to the serving pressure. Otherwise, you risk overcarbing the beer. Essentially you instantly carbed it to the full 30psi (depending on how long you shook it, but it doesn't take too long). What you should have done was put it on 13psi and shake - there is no chance to over carb that way.

To me is seems your beer is now overcarbonated. Then there's the issue with line length:

Since I do not have any experience with carbing kegged beer, I cant judge. In this page: learn.kegerator.com/force-carbonating-beer/ they say:

The other force-carbing method is similar but will carbonate at a faster rate. However, it’s important to note that it involves more effort.

First, attach the gas supply to the keg in the same manner as the first method. Once the system is hooked up, turn the gas supply up to 30 PSI.

Then, gently shake the keg to stir up the beer inside. You should immediately hear bubbling within the keg. Agitating the keg increases the contact area between CO2 and beer even further, promoting faster diffusion of CO2 into the beer.

Continue to shake the keg for 20-30 minutes then lower the pressure to 20 PSI and allow the keg to carbonate for 2-3 days. Check the carbonation levels and enjoy!

Should in this case keg be connected to the co2 bottle while shaking?

2m is NOT long enough. Bubbles coming out of solution means that there isn't enough resistance to keep it in suspension (i.e. lines are too short). I don't know which calculator you're using, but you say you doubled what it suggested - this would mean a suggested length of 1m, which will give you nothing but foam with a serving pressure of 14psi at serving temps.

This is the only line length calculator worth using, and I'm confident that if you plug your numbers into the calculator you'll see a suggested length of closer to 4m.

I used exactly that calculator and got 1.5m, so I took already premade line of 2m in length.

Can one take keg, put it on serving pressure and shake it for a ffew hours in order to get carbed beer on the same day?

Best and cheers,

 

[MagicMatt]

Should in this case keg be connected to the co2 bottle while shaking?

Yes, if you want to burst-carb a keg, the CO2 should be hooked up to the keg the entire time you are shaking it. Again though, I caution against doing what they tell you to do here unless as you are risking over carbing it if you happen to shake it too long. There is no way to tell how much or how long to shake if you are doing it at a higher pressure than you plan to serve it at.

When you shake a keg with CO2 attached, what you're doing is causing agitation and increasing the surface area for CO2 to diffuse into. More surface area means faster diffusion.

There is really no good reason to do this at 30psi though (unless your beer is around 70°F). The better option if you need it carbed immediately is to set the pressure according to the temperature of the beer and the volumes of CO2 you want in the beer, according to this chart:

If you follow this routine, you can never have over carbed beer since the pressure never exceeded what you desired.

Can one take keg, put it on serving pressure and shake it for a ffew hours in order to get carbed beer on the same day?

Yes, absolutely. So for example, if your beer was 40°F and you wanted about 2.5 volumes of CO2, you should set the regulator to about 12psi and shake it for about 15 minutes (or until you don't hear anymore gas going in). Let it set for about 20 minutes, then give it another round of shaking until you don't hear any more gas. Keep doing this until no more gas is going into the keg (should only be 2 or 3 rounds of shaking). You'll be pretty close to the 2.5vols (perhaps 90-95% there), and then you have nothing else to do. Simply leave the gas attached for serving purposes - no need to bleed the pressure or adjust the psi on the regulator.

I used exactly that calculator and got 1.5m, so I took already premade line of 2m in length.

I don't see how that's possible. Could you provide the numbers you used for the following:

CO2 Pressure
Hose Diameter (you mentioned "4mm", but I'm not familiar with that size tubing. Is it vinyl? Is that the ID? If so what is the OD?)
Vertical Distance from center of keg to tap
FG of beer

 

[day_trippr]

[...]2m is NOT long enough.[...]

I did a double-take on that last night but then noted the line ID in question is a scant 4mm - just 0.1575", vs .1875" for 3/16" ID lines. Cross sections are .0195 square inches vs .0276, former vs latter, a 30% difference.

Plug that .1575" ID into Mike's calculator with the pressure set to 12 psi and the result is 4.37 feet.

[edit] So my guess is that 30 psi shake was the coup de grace for this carbonation attempt.
That keg needs to be tamed before judgement on the dispensing geometry can have any validity...

Cheers!

 

[MagicMatt]

Yeah I suppose you're correct, but now I'm questioning the type of tubing used. Thin walled tube (think transfer tubing) won't provide the same resistance that a thicker-walled (standard beer line) tubing would, would it?

I know the resistance is dependent on flow rate, but I guess I always thought a thicker-walled tubing was needed to help hold the pressure.