How to Dehydrate Tomatoes
Slice tomatoes 1/4 to 3/8 inch or halve small ones, dry at 135F (57C) for 8 to 12+ hours until leathery and no longer moist. Store dry; never store home-dried tomatoes in oil at room temperature.
Dried tomatoes pack huge flavour into a small, shelf-friendly form. The method is simple, but tomatoes are wet and slightly acidic, so even slicing and honest doneness matter, and how you store them matters even more.
Best tomatoes and prep
Paste tomatoes such as Roma have thick walls and little juice, so they dry fastest and hold shape. Slicing tomatoes work too but take longer. Wash, then slice 1/4 to 3/8 inch, or halve small plum tomatoes. Scooping out the wet seed gel from large, juicy slices speeds drying, though it is optional. A light sprinkle of herbs or salt is a nice touch.
Drying time and temperature
Dry at about 135F (57C). Because tomatoes hold so much water, they take longer than most fruit:
| Cut | Approx time at 135F | Notes |
|---|---|---|
| Thin slices (1/4 in) | 8–10 hours | Leathery, flexible |
| Thick slices (3/8 in) | 10–12 hours | May need longer |
| Halved plum tomatoes | 12–18+ hours | Slowest; skin-side down |
Place skin-side down so juices do not pool through, and rotate trays if your machine has a vertical fan.
Doneness and storage
Done tomatoes are leathery and pliable with no moist or squishy spots; some prefer them dried to brittle for grinding into powder. Test a cooled piece. Cool fully, then store airtight and dry, in jars or, best for shelf life, vacuum sealed. Conditioning for a week (see how long dehydrated food lasts) catches any hidden moisture. Rehydrate in warm water before cooking, as covered in how to rehydrate dried food.
Frequently asked questions
Should I remove the seeds?
Optional. Leaving seeds in is fine; some remove the wet seed gel from large slicing tomatoes to speed drying. Paste types like Roma have less gel and dry faster.
Can I store dried tomatoes in olive oil?
Not at room temperature. Oil-packed dried tomatoes can pose a botulism risk unless kept refrigerated and used quickly, or prepared to a tested recipe. Store dry, then add oil just before use.
Why are mine still leathery in the middle?
Thick, juicy slices dry slowly. Cut more evenly, thin the wettest slices, and give them more time; test a cooled piece before storing.