Kegged beer: Draught system operation

The “Kegged beer” series explores draught system set-up and operation, plus how to pour from and change a keg. While it’s likely most helpful for people working in bars, restaurants, and bottle shops with kegged beers on offer, it’s interesting for all of us to learn more about beer’s journey from keg to glass! New to the series? Start here.

Now that we know about the key components, it’s time to look at how draught systems work.


Around the world, draught systems can be split into two basic groups:

  • those in which kegs are refrigerated (3 °C / 38 °F) and
  • those in which kegs are stored at cellar temperature (11-13 °C / 50-55 °F) or room temperature

Refrigerated storage

Refrigerated storage is always the best option for preserving beer freshness. (Why? Check out this article on beer storage for more details.)

In systems with refrigerated storage, the cold room and system temperature should be set to 3 °C (38 °F) and all kegs should be in the cold room for at least 24 hours prior to service.

This cools the kegs to the appropriate serving temperature and helps to prevent foaming while pouring.

Unrefrigerated storage

If kegs aren’t being kept refrigerated, they’ll either be stored at cellar temperature (11-13 °C / 50-55 °F) or room temperature.

As these temperatures are a bit too warm for service (draught beer is typically served around 3 °C / 38 °F), the beer in these kegs will need to be cooled.

To so do, the beer lines will either be run through a chiller and/or be bundled with coolant tubing (containing glycol or cold water) running alongside.


As you’ve likely gathered, for both systems temperature control is key… and is often the first thing to check when something goes wrong!

If beer isn’t pouring or is overly foamy (or “fobby”) when pouring, try these troubleshooting tips:

  1. (If using refrigerated storage) Have the kegs been in the cold room for at least 24 hours prior to service? (If the beer is too warm, the CO2 gas comes out of solution, causing foam in the lines.)
  2. Is the coupler is properly engaged? (The coupler lets gas in and pushes beer out, so if it’s not properly engaged the beer isn’t going to pour.)
  3. Are there any kinks or pinches in the beer line? (Think of a garden hose when you’re watering plants: if there’s a kink in the hose, the water doesn’t run. Same goes here for beer!)
  4. (If present in the system) Has the FOB detector been reset? (If the FOB detector isn’t reset after a keg change, the beer won’t pour.)

If – after all these checks – your beer is still pouring badly, contact a draught-trained professional for assistance. They are the only people who should be setting or adjusting gas pressure.


Draught-trained professionals can also assist with system maintenance, also known as line cleaning. (And it’s a good idea, too, as there are rather harsh chemicals involved. It’s crucial to ensure that the line clean is complete before beer is poured through the lines again.)

In order to ensure proper operation, draught systems need to be cleaned every every 14 days, at a minimum.

Line cleaning will also help to prevent the development of off-flavours in beer. (Read more about the off-flavours that result from dirty draught lines here.)

Now that our system is set-up and working properly, its time to learn how to pour!

Discovering Beer is not affiliated with or endorsed by the Cicerone® Certification Program.

Brought to you by Beer with Nat
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