Packaging
Beer line length
Too much foam at the tap? It is not the beer, it is a line that is too short. The tool gives the length that balances the pressure.
Result
Fill in the values and run the calculation, or try the example.
This is the calculation Krausi uses. Create an account to save it in a recipe or a brew.
Create my accountWhy balance the beer line?
It is the number one problem for people moving to kegs: a glass full of foam. The beer is at the right pressure in the keg, but it reaches the tap too fast and the gas breaks out all at once.
The answer is not to lower the pressure, which would make the beer lose its carbonation. You need to slow the beer down in the line: the longer and narrower the tubing, the more resistance it offers. The right length absorbs almost all of the keg pressure and lets the beer flow gently.
How is the line length calculated?
The line must absorb the keg pressure, minus what is needed to push the beer up to the tap and keep a slight flow:
length (m) = (pressure − 0.07 − 0.1 × height) / tubing resistanceThe pressure is the regulator setting, in bar. The height is that of the tap above the middle of the keg, in metres: each metre of rise uses up 0.1 bar. The remaining 0.07 bar ensures the flow at the tap.
Usual resistances: about 0.3 bar per metre for tubing with a 4 mm inside diameter, 0.15 bar per metre for 5 mm tubing.
Worked example
Values entered
- Keg serving pressure in bar: 0.8
- Height of the tap above the keg in m: 0.5
- Line resistance in bar/m: 0.3
Result from the tool
- Line length in metres
- 2.27 m
What the tool does not do
- The resistance of a tube depends on the manufacturer and the material: the values given are orders of magnitude.
- The tool does not account for the temperature of the line: warm tubing makes the first glass foam.
- It reports an error if the calculated length is negative: the pressure is too low to lift the beer.
Frequently asked questions
What tubing diameter for a keg?
Tubing with a 4 to 5 mm inside diameter for beer. The narrower it is, the more it slows the beer, and the shorter the line can be.
Why does my beer foam on the first glass?
The line and the tap are at room temperature: the beer warms up in them and releases its gas. The following glasses are better. Keep the line cold, or pour the first half-glass separately.
And with the assistant?
Ask Krausi the same question in plain language: he picks this tool, does the calculation and files the result in your project.
My keg is at 0.8 bar, the tap is 50 cm above it, 4 mm tubing. What line length?
You need 2.3 m of 4 mm tubing. Cut it a little longer: it is easier to shorten a line than to lengthen it.