Author Topic: Long Draw System CO2 Question  (Read 575 times)

Offline jeeyeop

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Long Draw System CO2 Question
« on: December 30, 2015, 02:45:48 AM »
So I'm working at a sports bar with a bunch of craft beers and I was wondering something (this coming from someone with no kegging experience).

With longer beer lines, you need to increase the pressure of the CO2 to overcome the line resistance. However, wouldn't increasing the pressure of the CO2 to these kegs eventually overcarbonate the beer in the keg?

Offline jeeyeop

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Re: Long Draw System CO2 Question
« Reply #1 on: December 30, 2015, 02:49:49 AM »
Also, I'm looking in page 20 of the Brewer's Associate Draught Beer Quality Manual, and in reference to coil/cold plate jockey box systems:

"They are also used with higher pressure CO2, which can overcarbonate a typical keg when tapped longer than a day."

I'm just not exactly sure why a jockey box system wouldn't be recommended for day-to-day use when a long draw system is used for day-to-day commercial purposes. I appreciate any information! Thanks!

Offline Thirsty_Monk

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Re: Long Draw System CO2 Question
« Reply #2 on: December 30, 2015, 03:49:16 AM »

So I'm working at a sports bar with a bunch of craft beers and I was wondering something (this coming from someone with no kegging experience).

With longer beer lines, you need to increase the pressure of the CO2 to overcome the line resistance. However, wouldn't increasing the pressure of the CO2 to these kegs eventually overcarbonate the beer in the keg?

You are correct.

There are a few things to deal with line pressure.

One is balance the system with lager diameter beer lines.

Use beer gas to increase keg pressure but do not over carbonate it.

Use of beer pump to move beer in lines.
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Offline Stevie

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Re: Long Draw System CO2 Question
« Reply #3 on: December 30, 2015, 03:53:00 AM »
Many long draw systems will utilize a beer gas blender. Larger diameter lines help as well.

Offline jeeyeop

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Re: Long Draw System CO2 Question
« Reply #4 on: December 30, 2015, 04:52:45 AM »
appreciate the help guys. just for my own better understanding though:

1. Lager lines = the wider diameter beer lines? I'm assuming this would ease the problem because there would be less line resistance therefore leading to less pressure required to serve?
     
     On another note, why is this called a lager line? What about lagers makes them require a wider line?

2. I'm assuming beer gas was suggested because it isn't 100% CO2 so it would impart less CO2 when serving?

3. A beer pump seems like a great way to reduce introducing excess CO2, but wouldn't this introduce more oxygen? Also, do commercial taprooms/bars use pumps nowadays? I'm wondering how much manual labor this would take.

Thanks again guys! Really appreciate the information!

Offline troybinso

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Re: Long Draw System CO2 Question
« Reply #5 on: December 30, 2015, 05:15:17 AM »
Pretty sure he meant larger (diameter ) lines.

How long do you have between the beer and the tap? 20 ft? 50 ft? You don't necessarily need beer gas, but it depends on a few basic things.

Beer temperature, co2 pressure, line length and line resistance.

If you can supply us with all of this info I am sure we can help you pour a perfect pint.

Offline jeeyeop

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Re: Long Draw System CO2 Question
« Reply #6 on: December 30, 2015, 05:20:14 AM »
Just started working at the bar. I'm just bussing tables there at the moment, this was just more out of my own curiosity. All I know for now is that the line is pretty long (probably several hundred feet) and kegs are kept in a cooler (~35F).

I was mainly just curious if the common practice of keeping kegs connected to CO2 tanks at high pressure would overcarbonate the beer dramatically in theory? Since the place has been open for 10+ years I would assume no, but some of the texts I read seem to imply doing so would overcarbonate the beer. Is it just not at consumer-noticeable levels?

Offline Stevie

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Re: Long Draw System CO2 Question
« Reply #7 on: December 30, 2015, 05:27:57 AM »
I can almost guarantee that they use a mixed gas, especially if they are also serving nitro beers. Likely even has a machine that concentrates the nitrogen from the air vs paying for nitrogen delivery.

Offline jeeyeop

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Re: Long Draw System CO2 Question
« Reply #8 on: December 30, 2015, 05:30:43 AM »
Next time I'm there on break I'm going to follow the lines to see where they go : / thanks again everyone!