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10-09-2013, 04:42 PM   #11
BigFloyd

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Dec 2012
Tyler, Texas
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Quote:
 Originally Posted by zachattack That's the conclusion that most of us have come to re: line length calculations. They make many assumptions that render them close to irrelevant for home systems. Remember that the only downside to a longer line is a slower pour. That's it. I like to think that if I can wait a month to brew, ferment and carbonate beer, I can wait an extra 5 seconds for a beer. Most of us use 10-12 feet (assuming standard 3/16" vinyl tubing) an call it a day.
This^^^^. The simple first step here is to install 12ft lines and then incrementally shorten them a bit at a time if needed.
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10-09-2013, 04:56 PM   #12
billl
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May 2012
Raleigh, NC
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You can also buy little mixers to stick down in the dip tube. They provide resistance similar to the longer lines. If you get your line length right for most of what you drink, you can keep some of those on hand for any higher carbed beers.

10-09-2013, 06:14 PM   #13
JuanMoore

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Oct 2009
The Old Pueblo
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Quote:
 Originally Posted by pmoneyismyfriend This can't possibly be correct
That depends on your definition of correct. The goal of that set of calculations is to result in a pour speed of ~1gal/min, and 2.2' of line would result in something very close to that given your figures, so in that sense it's correct.

Those equations and calculators ignore many of the basic laws of fluid mechanics, but they get away with it for commercial systems by making a few assumptions. They assume that the beer will be stored very cold (~36°), the carb level will be 2.5-2.7 vol, and the goal is to pour as fast as possible without losing a ton of beer to excessive foaming (which happens to be ~1 gal/min for 2.7 vol and temps <38°). Since those assumptions often don't apply to home systems or homebrewers, the equations and formulas are pretty useless for a lot of us.

Raising the temp just a couple degrees means that the flow needs to be slower/gentler in order to keep the CO2 from breaking out of solution. The same thing goes for carb levels over ~2.7vol. And since line resistance decreases as flow rate decreases, you need a much longer line to slow the flow down just a little bit.

Most of us don't really care if the average pint pour time is 1.5 seconds longer like a bar does. Instead, having a system that's flexible and capable of serving beers at a wider range of temperatures and with a wider variety of carb levels is typically more important, and well worth waiting an extra second or two for a pint to fill. This is the main reason you see many suggestions to avoid the calculators and formulas that result in a 1 gal/min flow rate, and instead to just use some extra long lines.

If you're interested, there is one line length calculator that doesn't ignore the laws of fluid mechanics. It doesn't do all of the work for you, but if you know the flow rate that won't cause excessive foaming for your specific beer temp and carb level, you can input that (in terms of time to fill a pint) and it will calculate the length of line required to achieve that flow rate. For many of us serving in the 2.3-2.6 vol and 38°-42° ranges, a 10-11 second pint fill time seems to work pretty well.
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11-01-2013, 02:36 PM   #14
pmoneyismyfriend
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Aug 2009
, wisconsin
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Wanted to pass along my results. I dailed the psi back to about 8 and got real weak pours and my beers seemed to be lacking carbonation. So now I am back up to 11 psi and have much improved pouring and carbonation levels. But 11 is where I was at when I started this post, so what the deuce? Perhaps in a month I'll be overcarbed again, but for now it's working splendid.
I have another question. I have a belgian strong that I have carbed to 4 volumes, which requires a setting of 23 psi @ 33 degrees. I have one regulator with a 4 way splitter. If I keep my psi @11 and, when wanting to pour the belgian, close off the other 3 and crank the psi to 23, and when finished with the pour dial the regulator back down to 11 and open up all the others again, do you think this practice will eventually weaken the carb level of the belgian?

11-01-2013, 02:42 PM   #15
pmoneyismyfriend
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Aug 2009
, wisconsin
Posts: 106
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Little mixers? What are those?

11-01-2013, 02:42 PM   #16
Yooper
Ale's What Cures You!

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Jun 2006
UP of Michigan, Winter Texan
Posts: 70,015
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Quote:
 Originally Posted by pmoneyismyfriend Wanted to pass along my results. I dailed the psi back to about 8 and got real weak pours and my beers seemed to be lacking carbonation. So now I am back up to 11 psi and have much improved pouring and carbonation levels. But 11 is where I was at when I started this post, so what the deuce? Perhaps in a month I'll be overcarbed again, but for now it's working splendid. I have another question. I have a belgian strong that I have carbed to 4 volumes, which requires a setting of 23 psi @ 33 degrees. I have one regulator with a 4 way splitter. If I keep my psi @11 and, when wanting to pour the belgian, close off the other 3 and crank the psi to 23, and when finished with the pour dial the regulator back down to 11 and open up all the others again, do you think this practice will eventually weaken the carb level of the belgian?
Yes. Adjusting the pressure up and down will exacerbate any foaming (as the gas/beer always seeks equilibrium) as well as reduce the carbonation level of the Belgian.

To have one at 23 and the rest at 11 psi requires a secondary regulator.
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