Let’s clear up the name first: almost nobody who makes “sun-dried” tomatoes uses the sun. Real sun-drying demands day after day of hot, bone-dry weather, the kind of climate a handful of regions actually have. Everywhere else, the fruit molds before it dries. The intensely flavored tomatoes you’re picturing come out of dehydrators and ovens, and they’re every bit as good. “Sun-dried” survives as a name the way “iceboxes” survived for a while, out of habit.
What makes drying worth your counter space is that it’s the one preserving method that transforms instead of just storing. Freezing and canning hand you back cooking tomatoes. Drying concentrates a pound of fresh fruit into a handful of chewy, sweet-savory intensity, closer to candy than to produce. A bushel that would swallow a freezer shelf fits into a couple of jars. Here’s the whole method, plus the powder trick that serious dryers consider the real prize.
Pick the right tomatoes (this matters more than the machine)
Drying is a war against water, so start with tomatoes that carry less of it. Oklahoma State Extension points at Romas and paste types for exactly this reason. High solids, low juice, which means faster drying and meatier results. The same logic that makes them sauce and canning champions in our variety breakdown makes them the drying default.
The other star is the cherry tomato, halved. Cherries dry into little flavor bombs, sweet enough that they disappear as snacks before reaching a jar. They’re the answer to the annual cherry-plant flood. Big juicy slicers dry fine too, they just take longer and shrink more dramatically. Treat them as the overflow option rather than the plan.
The dehydrator method (the default)
A dehydrator wins because it holds a low, even temperature with steady airflow for the long haul, unattended.
Prep is quick: wash, then slice. OSU’s numbers: paste tomatoes lengthwise in 1/2 to 3/4 inch slices, or simply halved or quartered; cherries halved. Arrange skin-side down on the trays, not touching, and salt lightly if you like (it nudges moisture out and seasons the result). Then set the machine to about 140 degrees and let it run. Expect 10 to 18 hours depending on thickness, juiciness, and your humidity. There’s no precise clock, and that’s normal; the tomato tells you when it’s done.
The doneness test: cool a piece to room temperature first, warm tomatoes lie, feeling softer than they are. Done means tough and leathery through crisp, with no moist, squishy, or tacky spots anywhere. When in doubt, dry longer. The piece that’s slightly over-dried keeps for a year, and the one with a damp center molds the jar.
The oven method (no gear required)
No dehydrator, no problem. Your oven does the same job with two compromises: it struggles to run as low, and it occupies the appliance all day. Set it to its lowest setting, ideally near 150 degrees, and arrange the tomatoes cut-side up on parchment-lined racks. Prop the door open a crack so moisture escapes instead of steaming the fruit. Expect several hours to most of a day, with a rotation of the pans partway through. The same cool-then-test doneness rule applies.
Honest verdict on the choice: if you’ll dry tomatoes once a summer, use the oven. If the habit sticks, and it tends to, a basic dehydrator pays for itself in energy and freed-up oven alone.
Condition, then store
Here’s the step that separates jars that keep from jars that mold, and most casual guides skip it: conditioning. Fresh-dried pieces vary slightly in leftover moisture. Before final storage, pack them loosely in a jar for about a week and shake it daily. The drier pieces pull moisture from the damper ones and everything equalizes. Any condensation on the glass is the jar failing the test, back into the dehydrator that batch goes.
Conditioned tomatoes store in airtight glass jars or containers somewhere cool, dark, and dry. OSU notes cooler storage directly stretches their life, with the freezer as the long-haul vault. The oil-packed jars you see at delis are a finishing move, not a storage method. Dried tomatoes packed in oil belong in the refrigerator, full stop, since oil’s airless environment is unsafe at room temperature over time. The full keeping-times picture across every method sits in our shelf life reference.
Using them, plus the powder secret
Dried tomatoes rejoin cooking three ways. Toss them straight into wet, simmered dishes, sauces, soups, stews, where they rehydrate in the pot while donating concentrated flavor. Soak them in warm water for twenty to thirty minutes for pastas and grain bowls. Or eat the cherry halves out of hand, which requires no instructions, only restraint. OSU offers one honest caveat worth passing on. Dried tomatoes never fully return to fresh texture, so they’re an ingredient, not a salad tomato resurrected. The recipe side of their career lives in our kitchen section.
And then there’s the move that converts drying from a novelty into a pantry strategy: powder. Blitz fully crisp-dried slices in a blender or spice grinder and you get pure tomato powder, a shelf-stable secret weapon. Whisked into hot water it becomes instant paste or sauce base; spooned into soups, chili, and rubs it adds tomato depth with zero liquid. One jar of powder is an entire sauce aisle in about four cubic inches.
If all this sounds appealing but your harvest math says “too much fruit, too little time,” remember the division of labor from the freezer guide. Freeze the bulk for cooking, dry the paste types and cherries for flavor. The two methods aren’t rivals, they’re departments, and the full preserving map shows where each shines. The end-of-season flood that funds all of it is covered in our harvest playbook.
Frequently asked questions
What temperature and how long to dehydrate tomatoes?
About 140 degrees for 10 to 18 hours, depending on slice thickness and juiciness. Slice paste tomatoes 1/2 to 3/4 inch thick, place skin-side down, and dry until pieces are leathery to crisp with no moist spots. Test only after cooling a piece to room temperature.
Are sun-dried tomatoes actually dried in the sun?
Almost never anymore. True sun-drying requires days of hot, arid weather that most climates can’t provide, so nearly all “sun-dried” tomatoes come from dehydrators and ovens. The name persists, but the flavor is identical, concentrated by drying, not by sunshine.
How do you dry tomatoes without a dehydrator?
In the oven at its lowest setting, around 150 degrees, cut-side up on lined racks with the door propped open a crack for moisture escape. It takes several hours to a day. It works fine for occasional batches; frequent dryers eventually find a dehydrator pays for itself.
How should dried tomatoes be stored?
Condition them first: a week loose in a jar, shaken daily, watching for condensation. Then store airtight in a cool, dark place, with the freezer for long-term keeping. Oil-packed dried tomatoes must live in the refrigerator, never at room temperature.
What can I do with dehydrated tomatoes?
Drop them into soups, sauces, and stews to rehydrate in the pot, or soak them 20 to 30 minutes for pasta and salads. Snack on dried cherry halves, or grind crisp-dried slices into tomato powder, an instant paste and soup base that stores in a spice jar.
Bottom line: slice them thick, dry them at 140 until leathery-to-crisp, condition the jar for a week, and store cool and dark. Oil-packed jars go in the fridge without exception. Skip the sun, trust the machine, and grind a batch to powder before winter, it’s the most pantry value a tomato harvest can buy. The rest of the preserving arsenal lives in our storage handbook.