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what happens to the stagnant beer in the serving lines?

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twd000

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I am trying to balance my system for the first time. Sitting at 3 C and 10 PSI -slow-and-steady carb, pour is OK, but a little fast (how fast should a pint fill?)
Pouring the first beer of the day, I get a slug of foam, then clear beer. Compared to later beers I seem to get less foam. I see everyone here recommending 10' of 3/16" beer line. I have 5'. My line are at the same temp as the keg (internal) and the shank is the only thing projecting outside. Does yesterday's beer go flat in the line, or stay carbonated? I calculate 7.4 fluid oz of liquid is contained in a 10' long, 3/16" ID line. So do you pour that first half-pint down the drip-tray?
 
I think it's more like 3 oz, but a math guy will figure this out quickly.

Now ask yourself....would flat beer cause foam? The beer in the line isn't any different than inside the keg...it's still under pressure.

It's a balance between pressure, temperature and length of your 3/16" tubing. Some quick reading of past threads should bring you up to speed. I think longer tubing might solve your problem.
 
You're right - 0.18 fl oz/ foot - I was using radius instead of diameter. Good to know it doesn't go flat. So 1.8 oz in a 10' line. Do you just coil it up inside your kegerator?
 
I don't have a tower. Shanks go straight through the wall of my fridge. But you're right that it takes some fluid flow to cool the shanks for the first pour. So I guess I do need to dump the first oz or two of foam until the shanks and faucet cool to beer temp.

So how quickly should a pint glass be filled at normal serving pressure? I feel like my beer is racing out of the faucet.
 
Remember that any beer upstream of the sealing mechanism in the faucet is still under pressure! So there's no driving force for CO2 to leave the liquid.
 
Sounds like your only problems with foaming are the faucets and shanks themselves getting warm because your drinking sessions are too far apart. After the first partial pour, they're adequately chilled by the beer from the lines and keg.
Those with towers have bigger issues because it's more mass that's allowed to warm, unless they use a forced air or glycol chiller.

You fortunately have an easy answer, if you want to take it- drink more frequently to keep those faucets cold ;)
 
I don't have a tower. Shanks go straight through the wall of my fridge. But you're right that it takes some fluid flow to cool the shanks for the first pour. So I guess I do need to dump the first oz or two of foam until the shanks and faucet cool to beer temp.

So how quickly should a pint glass be filled at normal serving pressure? I feel like my beer is racing out of the faucet.

Even with a warm faucet, there shouldn't be much foam at all in a balanced system if the beer lines really are the same temp as the bottom of the keg (where the beer is being drawn from). If you're getting 2oz of foam and then it pours nicely, that means that you either have some temperature stratification in your fridge (very common) or your beer is carbed slightly higher than what your serving pressure correlates to. Are you burst carbing or using the set and forget method?

Industry standard pour speed for bars is 1gal/min, which means a 16oz pint glass should take ~7.5 seconds to fill. I prefer extra long lines and a slower pour myself. I'm not running a busy bar or restaurant where the number of beers I can pour in an hour is important, and if I have time to drink a beer, I also have a few extra seconds to wait for it to pour. This way I never have to worry about foaming issues, even if I decide to carb something to 4 vol. How you balance your system is up to you though.
 
You'll also get some foam while the warm faucet cools down. After a pint or so, the beer will cool the faucet and you'll get better pours.

I wouldn't think that a faucet at room temperature would be enough to significantly warm the beer up enough to cause foaming. You're talking a 30°-35°F temperature difference that touching the beer for less than a second.
 
At my current settings, it only takes 3-4 seconds to fill a pint, so it sounds like it is coming out too fast. Maybe I will try one of the epoxy-mixing nozzles to slow things down. Is there a rule of thumb where 1 nozzle is equal to adding X ft. of 3/16" beer line?
 
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