Drying tomatoes preserves your garden's bounty with a fraction of the toil required for canning or freezing. As an added bonus, dried tomatoes take up little or no freezer space, freeing shelves for other foods. Plum or paste tomatoes with meaty flesh work best for drying.
For best results, use a commercial dehydrating unit.
Follow the manufacturers' directions for drying tomatoes in your dehydrator. Most dehydrators have a temperature control and recommend drying tomatoes at 130* to 142*F. Tomato slices take about 6 to 12 hours to dry.
You can try drying tomatoes in your oven but due to their high-moisture content, the results may vary. Drying in a standard oven takes 2 to 3 times longer than a dehydrator and during that time, you can't use your oven for other foods. The oven also requires significantly more energy than the dehydrator. If you still want to dry tomatoes in your oven, check with the manufacturer for specific instructions about drying foods.
Preparing the tomatoes. Wash tomatoes. Cut out cores. Cut tomatoes crosswise into 1/2-inch thick slices with a serrated knife. Spread them evenly in a single layer on the drying tray. Do not overlap edges. Place the tray in the dehydrator.
Pack dried tomatoes promptly in airtight, moisture-proof containers. Let stand at room temperature for 24 hours to allow the remaining moisture to distribute evenly in the tomatoes. Then, store in the refrigerator or freezer.