• 15.02.2023
  • 5 min

8 reasons not to wash glasses by hand in foodservice

Manually washing, drying and polishing glasses has a number of serious disadvantages compared to using a machine with an automated washing process. Inadequate hygiene safety is one of the most critical points. Low wash water temperature, type and dosage of detergent, insufficient mechanical pressure, flexible wash time and the risk of transferring germs can cause serious hygiene problems when glasswashing manually. This means that it is more of a matter of chance if the strict HACCP hygiene requirements are met during handwashing. Hygiene experts therefore advise against handwashing in foodservice as it does not offer reliable hygiene safety. Here is an overview of the issues that are particularly problematic when glasswashing by hand.


Hand washing: The biggest disadvantages at a glance!


No reliable hygiene safety
Danger of transferring germs
Increased personnel costs due to high time expense
Higher costs for water, energy and chemicals
Possible risk of injury and additional costs of glass breakage
Demotivation from monotonous task

Problem 1: Temperature

When washing by hand, there are limits to the water temperature: Generally, it can be maximum 40 °C otherwise there is a danger of scalding. For comparison: A glasswasher operates at over 60 °C. Given that grease is only effectively removed above 55 °C and germs are only inactivated above this temperature, washing by hand therefore always involves a hygiene risk.

A man stands at the sink of a bar counter and holds a hand into the running water to check the temperature

Problem 2: Danger of germs

As well as temperature, manual drying and polishing is also critical in terms of hygiene: There is a danger of transmitting pathogens. A used tea towel can harbour up to 100 million germs on an area of only 10 cm²! For comparison: When cleaning in a glasswasher, the washing process is automated and provides the required high temperatures and active wash times - using specific, gentle glasswashing detergents in exact doses. And: Using a special rinse aid means that the glasses come out of the machine in a way that they do not need to be re-polished with a cloth – which prevents the transfer of germs.

A man stands at the sink of a bar counter and dries a glass that has just been washed with a polishing cloth

Problem 3: Water consumption

Manual washing requires two full sinks: one with wash water and one with clear water. And: Depending on how much is washed and how heavy the soiling is, the water may need to be changed several times. This adds up – both in terms of the cost of the water and the associated energy costs. A direct comparison with a glasswasher is difficult, but it definitely requires less water. Rinse example: Using a warewasher from the Winterhalter UC Series uses only two litres of water per wash cycle – for an entire rack full of glasses.

A man stands behind a bar counter in front of two sinks filled to the brim with water and turns off the tap

Problem 4: Detergent dosage

Dosing detergent is a tricky thing when washing dishes by hand. Ultimately, everyone does it differently and according to feel. Or according to the principle,“More is better!” Whether the results then meet the high hygienic requirements is questionable. For our environment, this type of dosing is certainly not ideal. For comparison: As with the amount of water, a glasswasher is also very precise when it comes to dosing the chemicals and only doses as much as is absolutely necessary for cleanliness and hygiene.

A man stands at the sink of a bar counter and pours detergent from a bottle into the water

Problem 5: Pressure and duration

The optimum mechanical pressure is critical for a good wash result. When hand washing, this is at the discretion of the washer: they apply variable pressure depending on how dirty and fragile the glasses are. With some glass shapes, certain places cannot be reached at all with a washing-up brush. The care taken and whether the glasses are washed for a sufficiently long time depends on motivation and the time available. In comparison, the wash pressure and wash time is fixed in a glasswasher, exactly matched to the respective type of glass and always constant.

A man stands at the sink of a bar counter and turns a beer glass back and forth on the dish scrubbers

Problem 6: Possible risk of injury

There is a constant danger of glass breakage and therefore danger of injury both during the wash itself and when drying and polishing by hand. All it takes is a little too much pressure. For comparison: In a warewasher, the risk of glass breakage is minimal because the glasses are protected in a special glass rack. In Winterhalter machines, there is also variable wash pressure adjustment which ensures that fine glasses are not washed with too high a wash pressure.

A man stands at the sink of a bar counter and holds a broken beer glass and a splinter of glass in his hands

Problem 7: Time and cost expense

In times of personnel shortages in foodservice – and simultaneously rising personnel costs – this aspect should not be underestimated: washing, drying and polishing glasses by hand costs an enormous amount of time. And ties up valuable personnel resources. And that’s not all: the more often that glasses are washed by hand, the more glasses break and the higher the costs for glass breakage. Over time, this can be quite expensive. And there could be staff absences due to injury. This means: A foodservice operator who switches from hand washing to a glasswasher can significantly reduce both the personnel required and the costs associated with washing.

A man stands at the sink of a bar counter and, exhausted, supports himself with one arm on the edge of the sink

Problem 8: Motivation

While hand washing in foodservice is not comparable to washing up at home, the two have one thing in common: It is a pretty unpopular task – monotonous, time-consuming, exhausting. Those who have to do it usually don’t enjoy it: Hand washing demotivates staff and scares off new employees.

A man stands at the sink of a bar counter and polishes a glass with a dry cloth looking bored

Here’s how you recognise a badly washed beer glass.

A freshly washed beer glass with many drops of water on which the water film does not drain cleanly
After washing:
Individual water droplets remain clearly visible on the glass. Some drip downwards, some get stuck on the glass.
Freshly poured beer glass with collapsed beer foam and gas bubbles inside
After pouring:
The beer foam collapses. Tiny bubbles are formed on the inner wall.
Half drunk beer glass without beer foam and foam rings
After drinking:
There are no closed foam rings left on the inside wall of the glass, only scattered foam residues. “Please can we pay!”

Here’s how you recognise a professionally washed beer glass.

A freshly wasahed beer glass, on which the closed film of water runs off cleanly
After washing:
The closed water film runs off cleanly. There is at most a single drop of water left at the bottom.
Freshly poured beer glass with a beautiful beer foam
After pouring:
The beer foam forms a beautiful head on the freshly tapped beer.
Half drunk beer glass with several foam rings
After drinking:
Individual foam rings remain clearly visible on the inner wall of the glass. “Another, please!”
Practical know-how

What is a nucleation point?

You will find them not only on high-quality champagne and sparkling wine glasses, but also on beer glasses: a tiny roughened or protruding spot in the middle of the base of the glass – often in the form of an engraved logo. This is the “nucleation point”. It makes it easier for the carbonic acid dissolved in the drink to form bubbles: in the centre of the glass, these bubbles then rise up like pearls on a string, releasing fragrant aromas when they burst on the surface and ensuring beautiful bubbles or flawless foam. The nucleation point is particularly significant in perfectly washed glasses, as they are so clean that they no longer offer any points of attack for the carbonic acid.

lave verre frontal professionnel Winterhalter

The time has come!

Make the change now: to a professional solution for glasswashing. Foodservice professionals all over the world trust the expertise and experience of Winterhalter and count on a UC Series glasswasher.

Find out more now!
Restaurateur puts dirty glasses in a glass rack