Stemware Care and Maintenance: To keep your stemware beautiful you have to take care of it. Here are some basic tips to care for your crystal: - Do not store food or beverages in crystal containers for long periods of time. - Change the liquid or the container frequently to prevent build-ups. - Do not pour hot liquids into cold crystal, or cold liquids into hot crystal. The drastic change in temperature can crack the crystal. - Do not put crystal in a microwave, oven, or freezer. - When washing your glass: use mild soap, place a rubber mat in the sink, and use a faucet guard to prevent chipping. - Dry your crystal with a soft, lint-free cloth to prevent water spotting. - Crystal is not dishwasher-safe. Dishwasher detergent is corrosive and the heat from your dishwasher may crack your crystal.