- 2 Plum tomatoes
1. Slice plum tomatoes in half (or round tomatoes into quarters) and carefully scrape out the seeds, leaving the pulp intact. Turn halves pulp-side down and make a shallow slit about 1 inch long lengthwise into the skin. Turn back over and sprinkle lightly with salt to help the liquid drain.
2. Arrange tomatoes pulp-side up at least 1/2-inch apart on dehydrator trays and leave 1 to 2 inches in between racks for good air circulation.
Set dehydrator temperature to 135 to 140 F. (If your dehydrator does not have a thermostat, use a dependable oven thermometer on the bottom rack so you can monitor the temperature.)
3. You will most likely need at least 8 hours of drying time, more if the tomatoes are especially large and plump or if it is humid in your kitchen. Turn the tomatoes and rotate the racks as needed to promote even drying.
4. Keep your eye on them during the end of the process. The tomatoes should turn deep red and be completely dry yet still a bit pliable (not crispy). Test by touching with your finger. They should not feel tacky or sticky. Remove each tomato as it gets done, leaving thicker ones to finish.
5. Store dehydrated tomatoes in a zip-top bag, squeezing out the air, in a cool, dry place for up to 2 months. If you refrigerate or freeze the bags, the shelf life will be extended to 6 to 9 months.