For generations, silver manufacturers have warned consumers not to place silverware or silver-plated flatware in the dishwasher with stainless steel flatware. Grandmothers, antiques dealers and even dish detergent manufacturers also give out this common bit of advice. While the advice is on the mark, it might leave you wondering why mixing silver and stainless in the dishwasher is a bad idea.
Spots and Discoloration
When stainless steel and silver-plated flatware are placed together in the dishwasher, especially when the two metals are touching, a chemical reaction occurs, which leaves your bright, beautiful silver with dark spots and discolorations. These spots are not tarnish and cannot be removed with silver polish. The only way to remove them is to have your silver professionally refinished.
Washing Silver-Plate in the Dishwasher
Experts disagree as to whether or not you should wash silverware in the dishwasher at all. While Jeffrey Herman of the Society of American Silversmiths refers to dishwashers as "chambers of doom," other experts advise that washing silverware in the dishwasher can work well. They recommend first rinsing all food particles off with running water, then using only a small amount of dishwasher detergent that contains no citric acid or lemon. They do advise that pre-WWII silver knives should never be placed in the dishwasher. These pieces have hollow handles that are filled with resin, which can melt from the heat of the dishwasher, permanently damaging the piece.
Hand-washing Silver-plated Flatware
Silver-plated flatware and silverware are not the same thing. While silverware is typically solid sterling silver, silver-plated flatware is usually brass, nickel or stainless steel covered with a layer of silver. The silver plating is very thin, and can be rubbed off over time or scratched off with mishandling. The Society of American Silversmiths recommends hand-washing silver-plated flatware in warm water with a small amount of non-citrus soap, rinsing well and towel-drying immediately with a soft cloth.
The thin layer of silver plating can be rubbed off with repeated polishing, so it is important to prevent silver-plated items from becoming tarnished. When not using your silver-plated flatware, place the pieces in a silver storage cloth. Silver cloths are specially treated to absorb gases that cause silver to tarnish.