How long to dehydrate apples

Last reviewed July 2026.

Plan on about 6 hours for thin apple slices at 140°F — that is the number extension guidance gives, and the honest part is that it's a range, not a setting. Colorado State University Extension dries fruit at 140°F (60°C) and puts thin apple slices at roughly 6 hours, while stating plainly that the time "will depend on the size of the pieces being dried, humidity and the amount of air circulation." Thicker rings and a humid kitchen run longer; a thin, uniform ⅛-inch slice in dry air runs shorter. The temperature is fixed by the record; the clock is set by your slices.

Nesco, Excalibur, or any other dehydrator — the answer is the same

The most-searched version of this question adds a brand — how long in a Nesco, how long in an Excalibur. The brand is not what changes the answer. Every thermostatically controlled dehydrator set to 140°F is doing the same thing to the apple: holding drying-record temperature while air carries moisture away. A stronger fan (the Nesco FD-1040 Gardenmaster and the Excalibur 3926TB both push a lot of air) reaches "done" at the fast end of the range; a quieter unit sits at the slow end. Same temperature, same doneness test, a difference of an hour or two — not a different recipe. If your unit runs a fixed preset instead of a dial, that matters far more than the badge: a no-thermostat model like the Presto 06300 can't come down to fruit territory the way the marketing-headline max-temp implies it should.

"At 135 degrees" and "what temp" — you're in the right zone

People search how long to dehydrate apples at 135 degrees and what temp because the presets don't all read 140. You're fine. Extension fruit-drying guidance sits around 135–140°F for fruit; 135°F simply dries a touch slower than 140°F, and gentler heat is a feature, not a fault — drying fruit too hot risks case hardening, a dried shell sealing moisture inside that molds in the jar weeks later. If your dehydrator only offers 135°F or only 145°F, use it and judge by the fruit, not the dial. The 160°F+ ceiling the box marketing fights over is a jerky number and has nothing to do with apples.

Apples and bananas together

Bananas dry in the same 135–140°F range as apples, so a mixed tray is fine — with one caution: cut to similar thickness so they finish together, and expect banana to run a little longer because it goes in wetter and stickier. Both brown without help. Extension guidance says to pretreat fruit pieces by dipping in "an ascorbic acid, citric acid, lemon juice or sodium metabisulfite solution" before drying; a lemon-juice or ascorbic-acid dip keeps apple slices pale and does the same for banana.

Crispy apple chips vs leathery slices

This is the fork behind how to dehydrate apples to make them crispy. Two different targets:

• Leathery and pliable — the doneness for storage. Extension guidance dries fruit to leathery with no beads of moisture when you squeeze a cooled piece. This is what you condition and jar.
• Crispy chips — cut thinner (about ⅛ inch), and simply leave them in longer at the same 140°F until they snap instead of bend. Crispness is a function of thinner slices plus more time driving out more water — not a hotter setting.

An oven or convection oven works on the same logic — set it to its lowest setting, ideally near 140°F, prop the door for airflow, and expect it to run long. A Ninja air fryer on a dehydrate setting is a small, high-airflow chamber: it can crisp thin apple slices quickly, but the tiny basket dries a few slices at a time and needs watching, because a fast-moving fan turns "leathery" into "scorched" faster than a full-size dehydrator does. In every case the readiness test is the apple, not the timer.

The step after drying that decides whether the batch keeps

Extension guidance doesn't end when the machine switches off: dried fruit should be conditioned — packed loosely in jars and stirred daily for 4 to 10 days so residual moisture equalizes across the batch — before it's packaged for storage. It's the most-skipped step, and skipping it is how a "perfectly dried" batch grows mold in week three. No drying time, fast or slow, replaces it.

Sources — read them yourself

• Colorado State University Extension — Drying Fruits 9.309 (140°F, ~6 h for thin slices, pretreatment, conditioning 4–10 days)
• NCHFP — Drying foods at home (temperatures, conditioning)

Related: how long to dehydrate zucchini · how long to dehydrate tomatoes · why fruit dries at ~135–140°F, not 165°F.

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.