The clean solution

    Good glasses for gourmet guests

    The right glass is more than a stylish statement by the restaurateur

    Beverages play a central role in restaurants, bars and hotels around the globe. A fine wine, beer or long drink glass is more than just a stylish statement by the restaurateur - it noticeably enhances the guest's enjoyment. Find out here how to protect your precious glassware from glass corrosion and rattle damage.

    Shape and capacity

    A high-quality drink requires a suitable glass. Above all, the shape and the volume of the vessel play a very important role for enjoyment and taste: Thus, for a nice white wine, you should also use a classic white wine glass. In a large-volume glass, the aromas would be lost immediately. Red wines, on the other hand, develop more slowly - they need air to breathe. Burgundy or Pinot Noir therefore feel most at home in large, bulbous glasses that offer them plenty of air contact so that the complex aromas can develop.

    Glass storage

    However, the shape and size of a glass are only one aspect. For the glass to make a real contribution to enjoyment, it must also be really clean. Residues of washing-up liquid or incorrect storage can lead to a bad taste. For example, if glasses are stored with the opening facing downwards in cardboard boxes, they quickly take on the musty smell of the cardboard. Such foreign odours significantly impair wine aromas, for example.

    Washing glasses

    Many factors come together to achieve perfect dishwashing results. That includes glass quality, which plays a prominent role since glasses in the food-service industry have to go through hundreds or even thousands of wash cycles and still look like new. Leading glass manufacturers have optimised their glass manufacturing methods to such an extent that even expensive glasses no longer need to be washed by hand –  and the fact that they are dishwasher-proof means they tend to remain pristine for longer.

    Commercial dishwasher manufacturers have been working on the problem too, constantly developing their technologies further in order to achieve the best dishwashing results. One goal is to avoid what is known as glass corrosion. This is when chemical processes attack the basic structure of the material until the glass becomes unsightly and unusable over time.

    1,000 washes and as good as new

    Restaurateurs and hoteliers should view glassware as part of the value chain and include it in their calculations. ‘A high-quality glass can be washed around 1,000 times,’ says Klaus Völkner, Head of Sales for Germany at renowned German glass manufacturer Stölzle in the Saxon part of Lusatia, a region shared between Germany and Poland. But he also knows that, ‘That same glass will only make it through the dishwasher a maximum of 400 times’ – then, in most cases, it will end up in pieces being swept off the floor. Another mistake is to leave glasses in the machine for too long, exposing them to the risk of glass corrosion.

    The quality of the material is just one of the properties that can encourage such processes. Other decisive factors include water quality, wash cycle time, water temperature, detergent and rinse aid, not to mention, most importantly, how the dishwashing machine is operated and how it works.

    Glass corrosion

    Unfavourable chemical and physical phenomena can cause the surface of glasses to become ‘weathered’, a process referred to in the industry as glass corrosion. It is also known as glass disease, sick glass or glass illness. Close inspection reveals a microscopically thin roughening of the surface. The areas of glass affected by this process experience a change in their physical properties. This impairs the surface transparency and leads to microscopically fine cracking, also called crizzling.

    What does glass corrosion look like?

    Glass corrosion has different appearances:

    • Partial clouding
    • Full-surface clouding
    • Line corrision
    • Iridescence (shimmering)

    Glass corrosion is irreversible and cannot be polished away. It is important to make sure whether it is really glass corrosion or whether it is, for example, deposits caused by insufficient cleaning of the glasses.

    Is it glass corrosion?

    To find out if your glasses are really corroded, you should do the following.

    1. rinse the glass thoroughly with clear water (removes water-soluble salts, detergent and rinse aid residues, etc.) Coating removed? If not:
    2. clean and rinse the glass with a strong alkaline detergent or rinse with the correct dosage in dishwasher (removes grease and other organic substances). Coating removed? If not:
    3. clean the glass with a strong descaler solution, leave to soak and dry. (removes inorganic residues such as lime etc.). Coating removed? If not = glass corrosion

      Detection of corrosion in clean, clear glasses: 

      Take a clean glass in your hand, glide your (dry) thumb slowly over the surface (inside or outside) under pressure. If the thumb "sticks" to the surface and there is a squeaking sound when sliding over it, glass corrosion may already be present and you will probably soon be able to see a shimmering bluish coating.


      Glass is a very highly viscous liquid and has some water solubility, meaning it is soluble in water to a very small degree. The following is a list of possible causes of glass corrosion.

      Glass corrosion can be caused by:

      • Poor glass quality and errors in the manufacturing process
      • Too high temperatures in the rinsing process (>60°wash temperature; >70°clear rinse)
      • Too long rinsing time (>150 sec.)
      • Too low and too high detergent dosage (too low is worse)
      • Too frequent rinses (life expectancy is between 400-1000 cycles)
      • Aggressive water (0°dH / 0 µS/cm conductivity) without cleaner additive

      Clinking and rattling causes damage

      If washware is packed together too tightly in the dishwashing machine rack, they only need to briefly touch other glasses to cause a roughening of the surface and unsightly marks at the point of contact. Glasses should therefore never touch at the widest point of the glass bulge. The way to protect against chatter damage is to load the rack with plenty of ‘air’ gaps.

      Experts also agree that professional glassware management can make a meaningful and noticeable difference to a company's value creation strategy. Lastly, fine glassware contributes to a pleasant tone in the restaurant and tops off the fine dining experience. There is a reason why top-class, Michelin-starred restaurants tend to prefer hand-blown glasses. They complete the high-quality ambience of a restaurant in terms of optics.

      Take care of your precious glassware by choosing high-quality glasses when you buy them, avoiding too tightly packed washing baskets and also opting for quality products when it comes to glass management. For high-quality glasses, e.g. with printed decoration, the MEIKO ACTIVE product portfolio has special cleaners that ensure brilliant washing results, protect against glass corrosion and preserve the decoration for many years.