How long to dehydrate tomatoes

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Last reviewed October 2026.

Anywhere from 6 to 24 hours at 140°F — tomatoes are the wettest thing you'll put on a tray. Colorado State University Extension dries tomatoes at 140°F and gives a drying-time range of 6 to 24 hours, finished to crisp. That enormous spread isn't vagueness; it's water. A thin slice of a paste tomato in dry air finishes near the low end, while thick, juicy slicing tomatoes in a humid kitchen can run all day and into the next. The temperature is fixed by the record; the hours are set by how much juice has to leave.

Slice them, peel them, dip them

CSU cuts tomatoes into ½-inch-thick slices or ¾-inch sections. To make the skins slip, steam or dip in boiling water, then chill and peel; a dip in a citric-acid solution (1 teaspoon per quart of water, about 10 minutes) follows, and CSU lists it for tomatoes rather than blanching. Lay the pieces in a single layer no more than ½ inch deep. The doneness test is the same as for other vegetables: dry all the way to crisp, not leathery, for shelf storage.

Cherry tomatoes, and "what temp"

Cherry and grape tomatoes are searched constantly, usually with what temp attached. Same 140°F, and the same finish: crisp. CSU's preparation for tomatoes is to cut them — ½-inch slices or ¾-inch sections — and it gives no instruction for drying any tomato whole, so cut the small ones too rather than leaving them intact. Smaller pieces sit at the short end of the same 6–24 hour range; the temperature and the doneness test do not change with the size of the tomato.

Tomato powder

Powder is not a different process — it's a longer one. Dry the slices fully to crisp and brittle, with no flex and no cool moisture left, then grind the finished pieces in a spice grinder or blender. The single most important thing for powder is that the tomatoes are bone-dry before grinding: any residual moisture cakes the powder and shortens its shelf life. Store it airtight, and keep it sealed until use — tomato powder pulls moisture from the air fast and clumps.

Sun-dried tomatoes

"Sun-dried" in a dehydrator is the same 140°F drying — the name is about the style, not a special setting. Dry to a pliable, leathery state if you plan to pack them in oil for near-term use, or all the way to crisp for dry shelf storage. If you oil-pack them, that's a refrigerated, use-soon product; the fully dried, jarred version is the one that keeps at room temperature. When in doubt, dry further — a too-wet "sun-dried" tomato in oil is a spoilage risk, not a shortcut.

In an air fryer, or in an oven

A Ninja or other air fryer on a dehydrate setting can dry a thin single layer of tomato or cut cherry tomatoes, but the small basket and strong fan mean small batches and close watching — a high-airflow chamber crisps the thin edges well ahead of the wet centers. An oven runs the same 140°F logic, but only in an oven that can be set that low: UMN is explicit that one which cannot reach 140°F will cook the food instead of drying it. Set it in UMN's 140–150°F band for vegetables — not to whatever its minimum happens to be — and prop the door so moist air escapes. A home oven has no fan, so it dries more slowly than a dehydrator; no source puts a number on how much slower for tomatoes, so this page does not either. Dry until crisp and let the tomato, not the clock, end it.

Thickness, temperature and time, by source

Every value read from the linked source on 8 October 2026. NDSU: oven drying may take twice as long as a dehydrator.

Questions, answered from the record

How long does it take to dehydrate tomatoes?

6 to 24 hours at 140°F for 1/2-inch slices or 3/4-inch sections, dried until crisp, according to Colorado State University Extension. NDSU Extension lists 10 to 18 hours.

What temperature do you dehydrate tomatoes at?

140°F. Colorado State University Extension dries vegetables at 140°F, and NCHFP says food dehydrators are designed to dry foods at 140°F.

Do you peel tomatoes before dehydrating them?

Colorado State University Extension does: steam or dip them in boiling water to loosen the skins, chill and peel, then dip the pieces for 10 minutes in 1 teaspoon of citric acid per quart of water.

Drying meat too? 140°F is not a meat temperature

The 140°F that dries produce does not make jerky safe. NCHFP says jerky needs an internal 160°F to eliminate bacteria such as E. coli O157:H7 (read 8 October 2026). USDA's jerky guidance, quoted with the poultry number on the USDA jerky rule, says a dehydrator cannot be assumed to get the meat there. Which dehydrators publish a 160°F maximum at all: the best dehydrator for jerky. Why produce and meat need different dials: fruit dries at ~135–140°F, not 165°F.

Sources — read them yourself

• Colorado State University Extension — Drying Vegetables (tomatoes: 140°F, 6–24 h, ½″ slices / ¾″ sections, citric-acid dip, crisp)
• University of Minnesota Extension — Preserving food at home: Drying (oven 140–150°F for vegetables, ovens run 2–3× longer with no fan, case hardening)
• NCHFP — Drying foods at home (vegetable drying temperatures and doneness)
• NDSU Extension FN1588 — Drying Vegetables, Table 1 (University of Georgia times) (read 8 October 2026)

Gear these methods assume — mesh sheets keep wet tomato slices from sticking. Restocking? On Amazon ↗. Paid link; it changes nothing in the record above.

Related: apples · zucchini · herbs · blueberries · jalapeños · okra · why produce dries at ~135–140°F, not 165°F. · corn

Dehydrator Score indexes published specs and marketing claims against the USDA/NCHFP record, with attribution — we test nothing and give no safety advice. For drying guidance use NCHFP or your extension office. If a source changes, the page changes — the record wins.