Preferred shank / beer line diameter

I'm about to buy some shanks and beer lines for a newly built keezer. I think I remember someone telling me that 3/16 lines were the only way to go. However, my intuition tells me that they wouldn't be selling other diameters without a good reason.

So what are advantages / disadvantages of certain diameters of line / shanks? Feel free to say what your preferred line diameter is as well.

Thanks for your time.

The size of the line determines the amount of restriction, and how fast the beer flows ( given the same pressure). The only reason you would want anything larger than 3/16 is to reduce resistance. If you have a long draw glycol chilled system you might need 1/4-3/8 lines depending on how long the lines are.

Thanks for the quick reply. I'm probably going to get the 3/16 in that case, most people seem to confirm that.

Does the bore of the shank matter? Obviously it will add resistance, but its only a few inches. I did read somewhere that theoretically the change from 3/16 to, say, 1/4 can cause foaming. Is this a problem for some people?

I don't know about anyone else, but 3/16" ID is a gigantic ridiculous pain to get onto barbs and MFL fittings and such. 1/4" line goes on perfectly, and it only needs to be marginally longer to maintain the same resistance.


The change from 3/16 to 1/4 shouldn't cause foaming. The beer is still under pressure when it's inside the line, and all the connections are a distinct change in diameter anyway (hose barbs, beer going around the poppet valve, etc).

Hypnolobster said:

I don't know about anyone else, but 3/16" ID is a gigantic ridiculous pain to get onto barbs and MFL fittings and such. 1/4" line goes on perfectly, and it only needs to be marginally longer to maintain the same resistance.

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I beg to differ. A 1/4" line needs to be roughly 3 times longer than a 3/16" line to achieve the same pressure drop.

Read here:
http://www.winning-homebrew.com/dispensing-your-beer.html

Also, it's not that hard to push 3/16" tubing onto properly sized shanks/barbed fittings. It can be slightly difficult to work with when using oversized (1/4") barbs. Try warming the tubing with a heat gun or hair dryer if you're having trouble.

It seems to make more sense to get 3/16 rather than anything else. My reasoning being, that it would be better to start off with high resistance in 10' of line and have flat beer, then cut down the line until I get to an optimal level of resistance. This seems to make more sense than having to deal with 20 feet of 1/4 line just to get the resistance that you want...

Actually, too much resistance will result in a slow, slightly overcarbonated pour with no head. Too little resistance will result in a fast, foamy pour.

The resistance is just right when you don't have to wait around all day for a pint, and there's 1/2" to 1-1/2" of foam on top.

Line balancing can be finicky, and it's always better to err on the conservative side (i.e., a little more resistance rather than too little). Realize that ideal line length changes based on temperature, pressure, and carbonation level. Balance your system for the highest temperature, pressure, and carbonation level expected. Accept a slightly slow pour when serving a lesser carbonated beer under relatively low pressure.

I balance my system for a pour at 10.5 psi and 37º F (2.5 volumes of carbonation). At 18" tap height from the top of the keg, that equates to about 6 feet of 3/16" line. The pour is fairly fast, but as long as you get a quick and clean tap on/off motion, the foam is minimal.

I am about to set mine up as well, do you guys still use 3/16 with the McMaster Mixer Nozzle's and how long of lines should I use with them?