A single sun-dried tomato can change the entire flavor of a meal. A tomato that is dehydrated in the sun develops an intense flavor and chewy texture without losing the nutrients, including vitamins A and C and the antioxidant lycopene, that make tomatoes a valuable part of your diet. Sun-dried tomatoes will last far longer than their fresh counterparts, and freezing extends their usability, but improper storage will shorten their shelf life.
Storing Oil-Packed Tomatoes
Sun-dried tomatoes stored in oil won't last as long as those stored dry. Check the expiration date on a container of oil-packed tomatoes; it should be anywhere from one to two years. Sun-dried tomatoes stored in oil are shelf-stable until opened, but once you break the seal you'll need to store them in the refrigerator. There, they'll stay edible for up to six months. Check for signs of mold or a rancid smell before using the tomatoes. The oil will solidify and turn white in the refrigerator but will return to liquid after 30 minutes or so left out on the counter.
Storing Dry Tomatoes
If you buy sun-dried tomatoes loose or in a container without liquid, place them in a zippered plastic bag, a jar with screw-on lid or plastic or a glass container with an airtight lid. Don't put them in contact with metal. Squeeze any air out of a plastic bag before sealing it; if you're using a container, pack the sun-dried tomatoes in tightly so they fill the entire container. Store the tomatoes in a cool, dark cabinet for up to a year. After this point, they'll start to lose their flavor and nutritional value.
Once you've stored dry sun-dried tomatoes in a bag or container, you can place the entire package in the freezer and the tomatoes will last up to two years. Freezing oil-packed tomatoes takes a bit more work; if you freeze the entire container you'll have to thaw the entire thing in order to remove a single tomato. Instead, cover a cookie sheet with waxed paper and spread the tomatoes out so no two are touching. Each tomato will have a small pool of oil. Freeze the sheets for an hour or until the tomatoes are frozen through, then pull the tomatoes off the waxed paper and place them in a plastic freezer bag or glass container with an airtight lid. They'll last in the freezer for up to a year, but try to use them within three months for the best flavor.
Once you've pulled your tomatoes out of the fridge or cabinet, or let your frozen sun-dried tomatoes thaw out -- their small size means this process takes only an hour or so -- you may either use them as is or reconstitute them by soaking them in water, stock or even wine. Let them sit in the liquid for up to two hours on your counter, or in the refrigerator overnight. Chop the tomatoes and add them to cold pasta salad or garlic hummus, sprinkle them on a spinach pizza or use them to top burgers or roasted-vegetable sandwiches.