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Commercial Glasswasher Results Guide

The Glasswasher is the means of maintaining a good quality of finish on the glasses, but it is the glass that presents your product (wines spirits & beer) to the customer.

A good result from the Glasswasher is therefore extremely important to sales and customer satisfaction.

What is not acceptable to the customer:

Dirty Glasses:

In nearly all cases the problem of dirty glasses originates from the pint glasses and most prominently from Real Ales. However, the first complaints will probably be about the wine or spirit glasses.

Once the problem with the pint glasses is resolved then the wine glasses will improve.

What to look for:


Take a moist white serviette and wipe the inside of a supposedly clean pint glass. If there is a brown deposit showing then there is a protein build up on the glass.

Alternatively, turn a pint glass upside down and look at the outer ring of the base. The poor results will be magnified and show up as a brown 'halo'. The white Logo of a 'Headkeeper' will turn brown.

If there is a film of bubbles on the inside of a larger glass then it is a sure sign that the glass is not clean. The bubbles will only stick to an impurity.


Wild Yeast: Look for Beige or even a black film or deposit (build up of growing yeast cells) around the door and door hinges. If this exists then it will transfer to all of the glasses and give poor results.


  • Leave the machine door open overnight. This will allow the Bacteria and Algae to dry out and then usually it dies. The machine should then be easier to keep clean.
  • If the poor results are only slightly poor then it is possible to solve the problem by increasing the detergent dosage manually.
  • If the results are very poor then it will be necessary to use a strong Chlorinated Powder detergent to resolve the problem. This is a specially formulated product designed to RENOVATE glasses back to a satisfactory condition. It will also sterilise the inside of the cabinet of the Glasswasher.
  • Always ensure that there is detergent container never runs dry. Dosing failure results in protein build up which is difficult to remove and 'Renovate' may have to be used.
  • Check that the glasses are not coming out too hot. If they are then this will bake a film on the glass, so call an engineer to rectify the problem.

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Flat Beer/Poor Head Retention:

There are two main causes of this problem:

  1. The head is killed by chemicals on the glass from excessive amounts of rinse aid and detergent, fats from coffee cups or from customer's lips when they have been eating crisps/peanuts.
  2. The head is not regenerated from rising gases due to either the glass being too smooth or there is a film on the glass. The head of the beer will be acceptable when it is first poured but is not maintained by "Effervescence" (bubbles continually released).

These problems are made worse if the Larger is low in CO2, or if the glass surface is very smooth. This can be the case with toughened glassware, as gas bubbles form more easily on a roughened surface.


  • Ensure that the rinse aid is of good quality.
  • Ensure that the rinse aid is not over dosing.
  • Ensure that the rinse water pressure is sufficient and consistent.
  • In persistent cases it may be necessary to use the 'Headkeeper' type of glass.

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Spots & Streaks/Glasses not Drying:

As the glasses are taken from the Glasswasher they will appear with a “raindrops on the windowpane" effect and the water is not 'sheeting' off of the glass.

This can be caused by:
Oil film on the glass -
(Possibly from drying with a tea towel, which has been washed, using a fabric conditioner).
Beer or protein film on the glass -
(A high level of 'salts' in the water, which are not removed by the water softener).


  • Do not dry with tea towels, as this film is very difficult to remove.
  • Ensure that the rinse pressure is adequate. A boost pump may be needed.
  • Check that the rinse aid is being used.
  • Check that detergent is being used consistently.

Cloudy Glasses:

Water quality throughout the UK is no longer consistent. In many cases sites, which have had good results, can suddenly experience a cloud or bloom appearing on their glasses. This effect is quite different to a protein film and is not brown when wiped with a white serviette.

It is caused by minerals, which are totally dissolved in the water drying on to the glass i.e. put a clean glass into the glasswasher, and it comes out cloudy.


The cure is expensive and requires the fitting of one or two demineralising cartridges (£600ea). Depending on water quality they need to be exchanged at about 3-4 months (£160). Reverse Osmosis is another alternative with an initial cost of £3000 and annual maintenance of £400.

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Etching (permanent damage):

Etching is permanently damaged to the glass, generally as a slightly white frosty pattern. Washing or scrubbing will not remove it! A customer may see this as a dirty glass.

Etching will occur on all glasses over a long period but normally they are lost or broken before that happens.


  • Remove the glasses from the glasswasher as soon as possible. High temperatures will accelerate the etching process.
  • Do not use cheap high caustic detergents. Once they have cleaned the glass they will then attack it.
  • Check to see if only one make of glass has the problem. In most cases certain makes of glasses will etch where others won't. Change brands!

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General Tips:

  • Do not tip beer or slops into the machine, as the detergent will be neutralised by the additional protein and the cleaning will be ineffective.
  • Remove all fruit peel and cocktail sticks from the glasses as they will block the wash jets and give poor results.
  • Remove & clean all filters daily. A poor wash action will cause bad results.
  • Regenerate the water softener weekly. If it is not done then the life of the machine will be shortened and more detergent will be needed to overcome the effects of hard water.