Don’t Lose Your Head

Picture the scene, it’s a busy Saturday night, the pub is full and the customers are three deep at the bar when somebody complains that the lager is flat.

If you’ve not experienced this yet I’m sure you will at some stage but what do you do.

Firstly, you need to find out if it’s the beer, the dispense equipment or the glasses. The following steps may help you decide.

Check the beer in the glass by dropping in a coin, if it starts to fizz you know it’s not the beer. You can also try stirring the beer with a small spoon or your finger, again if it fizzes then it’s not the beer. You now need to start eliminating the equipment. Make sure you have the correct nozzle on the tap and if it has a small disc with holes in it normally, make sure that it’s fitted correctly in the nozzle.

Next thing to check is the glassware. An easy way to do this is to do a water break test.


  • Take a clean glass off the shelf and fill it with cold water to the brim.
  • Pour the water out and invert the glass.
  • Dry the outside of the glass
  • If the water runs off in a continuous film around the rim of the glass then its clean
  • If it pools inside the glass into spots and rivulets then the glass is dirty and has a non rinsing film on it and will need cleaning.


The best way to clean the glasses is to use a renovate powder to remove any films from the glass and bring them back to life.

The next thing to check is that the glasswasher has the correct detergents specific for glass washers. Never use dish washer detergents on a glass washer, it’s not going to work correctly. Make sure the glass washer is clean and no one’s put any coffee cups or milk based drinks in it. The fat in the milk will get into the rinse water and contaminate it, this then deposits a thin film of fat on the glasses and will show up on the water break test.

Lastly check that the glasses are bone dry. Glassware with the nucleation “widgets” on the base will only work correctly when dry. It takes around 40 minutes for a glass to dry fully and on a busy night this can put a strain on your glass stock. The best way to get glasses dry quickly is to use an Airack, ( ). This is a machine that blows cool air into the glasses after they have been washed and will dry them in 2 minutes. Well worth considering in a busy pub as you can only sell beer if you have clean dry glassware at peak periods. As a stop gap when your busy you could put the glasses on the shelf the right way up so they dry quicker, they may spot a bit but at least you will have dry glasses to fill.

If you’ve tried all of this and still have a problem, check in the cellar. Are the gas bottles full? Are all the gas valves turned on? Is the keg fitting correctly connected making sure that the gas line is not kinked? If nothing else has worked the last thing you could try is putting another keg on and pulling it through.

Finally, if all else fails then it looks like a call to your friendly technical services engineer will be needed but at least by going through these checks you’ve done your bit to get it right.

In my experience the majority of flat beer problems are down to the glasses so look after them and in the words of Rudyard Kipling, “Don’t lose your head when all about are losing theirs”.