CARING FOR YOUR GLASS
Glass should be stored in dry, ventilated conditions as damp can cause white cloudy stains. A glass wrapped in damp newspaper can be permanently marked with the newsprint and a damp glass can be permanently stained in a few hours by strong sunlight. Decanters should not be stored with their stoppers in place in case there is remaining damp inside.
In common with ceramics, glassware should never be put in a dishwasher as the salts and detergents may harm the surface and cause cloudiness. Wash glass carefully by hand in a plastic bowl with a towel or foam mat on the bottom. Use warm water and a little washing-up liquid and wash only one piece at a time. If the glass is very dirty or greasy, a few drops of household ammonia can be added to the water but not if the piece is gilded. Dry carefully and thoroughly while the glass is still warm using a lint-free cloth. A warm hair dryer can be used, well away from the sink and water, to dry the inside of decanters or other vessels or place them upside down in an airing cupboard for 24 hours. You can also roll up paper kitchen towel, push it into a decanter until it touches the bottom, being careful not to loose the end, and remove it 24 hours later.
Hard water left in glass can leave deposits of calcium carbonate, and alcohol will often leave dark stains which can be treated with a solution of denture cleaner and warm water or with an organic acid such as citric acid, white vinegar or a mixture of one tablespoon of salt to a quarter of a pint of vinegar. Whichever is used, leave in the glass or decanter for 24 hours, shaking occasionally, then rinse and dry thoroughly. If stains are still there, repeat the process although it may not be possible to remove them completely. Do not use stronger acids as they may etch into old glass. Alcohol-based perfume bottle stains can be treated with methylated spirits or pure alcohol. This should be changed every hour or so until the stains have gone. If attempts to clean glass using these methods fail, the process can be done professionally for a relatively low cost. Specialist glass dealers can usually advise on reputable cleaners.
Glass which has become ‘crizzled’ with a network of fine surface cracks and all ancient excavated glass should not be washed, and should be handled as little as possible.
Reproduced with kind permission of LAPADA