How-to Guide
Drying Tomatoes at Home: Dehydrator vs Oven, Conditioning, and Storage
The short answer
Tomatoes are one of the easier things to dry and they do not need blanching, but because they are so juicy the drying is slow. Oven-dry at the lowest setting: preheat to 140 to 150 F, then hold a consistent 140 F with the door propped open so moist air escapes; a food dehydrator holds low temperatures more reliably. Slice evenly, dry until leathery to crisp with no visible moisture when you tear a piece.
Conditioning is the step people skip and it matters most for high-moisture produce like tomatoes. After drying, let the pieces cool, pack them loosely in jars about two-thirds full, seal, and leave for several days, shaking daily to redistribute residual moisture between drier and wetter pieces. If you see condensation on the jar, the tomatoes are not dry enough; return them to the dehydrator.
Store conditioned tomatoes in clean, dry, airtight glass jars in a cool, dark, dry place; So Easy to Preserve gives a recommended storage time of 6 to 12 months for dried vegetables. Packing dried tomatoes in oil is a different product with a botulism risk, so keep those refrigerated and use a tested method.
Dehydrator or oven
A dehydrator is the more forgiving tool because it holds a steady low temperature and moves air. Slice tomatoes evenly (halves for cherry types, slices for larger ones), lay them cut-side up in a single layer, and dry until they are leathery and pliable to crisp. Thicker, juicier slices take many hours; thin ones dry faster.
No dehydrator is fine. Oven-dry by preheating to the lowest setting, 140 to 150 F, then propping the oven door open and adjusting the thermostat to hold a consistent 140 F so moisture can escape. Watch them near the end, since ovens run hotter than dehydrators and edges scorch. Tomatoes do not need blanching before drying.
Conditioning: the forgotten step
- 1Cool completely — Let the dried tomatoes cool to room temperature before packing. Packing warm traps steam.
- 2Pack loosely and seal — Fill clean, dry jars about two-thirds full with the cooled pieces and seal them. The air space lets moisture equalize.
- 3Shake daily for several days — Over the next several days, shake the jars daily so moisture redistributes between drier and slightly wetter pieces.
- 4Check for condensation — If any condensation or moisture beads appear inside the jar, the tomatoes were not dry enough. Return them to the dehydrator or oven and dry longer, then condition again.
→ Conditioning matters most for high-moisture produce like tomatoes; it is often the forgotten step in dehydrating. Very dry, crisp vegetables like beans or peppers do not need it.
Storing dried tomatoes, and the oil warning
Store fully dried, conditioned tomatoes in airtight glass jars with tight lids, kept in a cool, dark, dry place. The So Easy to Preserve guidance is a recommended storage time of 6 to 12 months for dried vegetables. Check jars in the first week for any sign of moisture and re-dry if needed.
One safety note: dried tomatoes packed in oil are not the same as dry-stored ones. Oil creates an oxygen-free environment around a low-acid food, which is the classic setup for Clostridium botulinum. Keep oil-packed tomatoes refrigerated, make small amounts, and follow a tested recipe rather than storing them at room temperature.
⚠ Do not store home-dried tomatoes in oil at room temperature. Oil plus a low-acid food is an anaerobic, botulism-risk environment; refrigerate oil-packed tomatoes and use them quickly.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- Clemson HGIC / So Easy to Preserve - Drying Vegetables — To oven dry, preheat at the lowest setting (140 to 150 F), then adjust the thermostat and prop the oven door open to hold a consistent 140 F and let moist air escape; vegetables are dried until brittle/crisp; store dried vegetables in a glass jar with a tight-fitting lid in a cool, dry, dark place with a recommended storage time of 6 to 12 months.
- Iowa State University Extension - Conditioning Dried Foods — Conditioning is most important for high-moisture fruit including tomatoes and is often the forgotten step in dehydrating; pack cooled dried pieces loosely in jars about two-thirds full, seal, and shake daily for several days to equalize residual moisture; if condensation appears inside the jar the food is not dry enough and must be returned to the dehydrator.
- NCHFP - Drying Fruits and Vegetables — Tomatoes are dried; blanching slows or stops enzyme action that causes loss of flavor, color and texture; dried products are stored tightly sealed in a cool, dry place.