Milk is perishable. To preserve its safety and quality, the following tips are recommended: Refrigerate milk at 40°F or colder as soon as possible after purchase and store in the original container. Freezing milk is not recommended. It causes undesirable changes in texture and appearance. Return milk to the refrigerator immediately after pouring out the amount needed. Never return unused milk to the original container. Keep milk containers closed to prevent the absorption of other flavors. Absorbed flavors may change the taste, but the milk will still be safe. Protect milk from exposure to strong light because light can reduce its riboflavin content and can also affect flavor. Look for the "sell by" or "pull" dates on milk cartons. If properly cared for, milk generally stays fresh for 2 to 3 days after this date. Some dairy processors guarantee their products for a specific time after this date. Ask your grocer for more details. Keep canned milks like evaporated and sweetened condensed milks in a cool dry place and invert the cans every 2 months. These milks generally keep for about a year at room temperature. Once opened, canned milk should be poured into an opaque covered container, refrigerated and used within a few days. Store dry milks in a cool, dry place and keep in an airtight container after opening. Once reconstituted, dry milk should be refrigerated and handled like other fluid milks. Microwaving milk is not recommended as a way to extend milk's shelf life or as a means of pasteurization.