Dehydrating

Pulls moisture out of food until microbes can no longer grow. Herbs, fruit leather, dried fruit, jerky, and vegetable powders — all shelf-stable for months.

How it works

You can dehydrate in a dedicated machine, in a low oven, or for some foods, by air-drying. Each method has its own temperature and time targets.

When to use this method

Best for: herbs (parsley, basil, thyme), fruit leather, apple rings, banana chips, jerky (meat, see safety notes), tomato powder, mushrooms, and vegetable chips.

Authority sources

How dehydrating preserves food

Microbes need water to grow. Dehydrating reduces water content below the threshold most bacteria, yeasts, and moulds can survive — typically below 20% water content for fruit and below 10% for vegetables.

The food becomes shelf-stable without refrigeration. Most dehydrated foods keep their quality for 6–12 months in airtight containers at room temperature; vacuum-sealed they go 1–2 years.

The trade-off versus canning: dehydration changes texture (apples become chewy, herbs become brittle) and concentrates flavour. The trade-off versus freezing: dehydrated food doesn't need a power-dependent storage system.

Equipment: dehydrator vs oven vs air

A dedicated electric dehydrator is the most reliable. It maintains low temperatures (35–70 °C / 95–160 °F) with constant airflow. Stackable-tray models (Excalibur, Nesco) cost CAD $80–250 in Canada; horizontal-airflow units are more even but pricier. See our Canadian dehydrator buying guide and how to clean and maintain it.
A low oven works if it goes below 90 °C (200 °F). Many ovens won't go that low, and the bigger problem is airflow — without it, the food steams instead of drying. Prop the oven door open a few centimetres. Full method in the no-dehydrator section below.
Air-drying works for hard herbs (rosemary, thyme, sage, oregano) in a dry, ventilated spot. Tie stems in small bundles, hang upside-down in a paper bag, wait 1–2 weeks.
A sun dryer or solar dehydrator is rarely practical in Canada — our summer humidity is too high in most regions for reliable sun-drying. Better to invest in an electric dehydrator.

Comparing gear across methods? See our Canadian preserving equipment guides.

Temperature ranges by food

These are the widely-published ranges for home dehydrators. The exact setting depends on your machine — check its manual.

Herbs: 35–40 °C / 95–105 °F. Low and slow preserves the volatile oils that carry flavour. Higher temperatures burn off the very compounds you're trying to keep.
Vegetables: 50–55 °C / 125–135 °F. Higher than herbs, lower than fruit. Most vegetables need 6–14 hours.
Fruit and fruit leather: 55–65 °C / 135–150 °F. Higher temperature for higher sugar content. Most fruit needs 6–24 hours.
Jerky (meat): 65–70 °C / 150–160 °F. Then verify with an oven step: Health Canada recommends an additional 10 minutes at 75 °C (165 °F) in the oven after dehydration to ensure pathogen safety. This is the most common safety oversight in home jerky.

How long to dehydrate: times for common foods

Times below assume an electric dehydrator with stable airflow, a single layer of food, and pieces sliced to roughly the thickness shown. Oven-drying runs roughly 30–50% longer because airflow is weaker. Real-world times swing ±30% with humidity, machine model, and slice thickness — the dryness test is the source of truth, not the clock.

Food	Prep	Temperature	Typical time
Apple rings or slices	5 mm; lemon-water dip	60 °C / 140 °F	6–12 h
Banana chips	5 mm; lemon-water dip	60 °C / 140 °F	6–10 h
Pear slices	5 mm; lemon-water dip	60 °C / 140 °F	8–14 h
Strawberries (halved)	halved or 5 mm sliced	55 °C / 135 °F	8–14 h
Blueberries	whole; check or "blanch-crack" the skins first	55 °C / 135 °F	10–18 h
Fruit leather	3 mm purée on liner	55–60 °C / 135–140 °F	4–8 h
Tomato slices	5–8 mm	55 °C / 135 °F	8–14 h
Zucchini chips	3–5 mm	55 °C / 135 °F	6–10 h
Carrots	3 mm; blanch 2–3 min	55 °C / 135 °F	6–10 h
Green beans	whole or split; blanch 2–3 min	55 °C / 135 °F	6–12 h
Corn (off the cob)	blanch 2–3 min	55 °C / 135 °F	6–12 h
Peppers	5 mm strips	55 °C / 135 °F	6–10 h
Mushrooms	3–5 mm	50 °C / 125 °F	4–8 h
Kale (chips)	de-stem; whole leaf	50 °C / 125 °F	2–4 h
Hardy herbs (rosemary, thyme, sage, oregano)	whole sprigs	35–40 °C / 95–105 °F	1–4 h
Tender herbs (basil, parsley, mint, cilantro)	de-stem; whole leaves	35–40 °C / 95–105 °F	2–6 h
Beef or game jerky	3–5 mm strips; marinated	65–70 °C / 150–160 °F + post-dry oven step	4–8 h plus 10 min at 75 °C

If a slice is sticky, moist, or cool to the touch when you pull it, it isn't dry yet — add another hour and re-test. The cost of a too-long dehydrator run is brittle food; the cost of a too-short run is mould in the jar.

For the full lookup — including what you can and can't dehydrate — see the what-can-you-dehydrate chart.

How to dehydrate without a dehydrator

You don't need to buy a machine to start. The practical no-dehydrator methods are oven drying and air drying, plus a niche summer trick. Each works well for some foods and poorly for others — and our full no-dehydrator guide walks through each in more depth.

Dehydrating in the oven

An oven can stand in for a dehydrator as long as it holds a temperature at or below about 90 °C (200 °F). Many Canadian home ovens bottom out at 75–95 °C; if yours doesn't go that low, set it to its minimum and prop the door open.

Prop the door open 5–10 cm with a wooden spoon or a folded oven mitt. This is the single biggest difference between oven drying and oven baking — the open door lets moisture escape so the food dries instead of steaming or roasting.
Add airflow. A small fan aimed at the open door, or a convection setting, dramatically cuts drying time and improves evenness.
Use racks, not solid sheet pans. Place wire cooling racks on baking sheets so air moves around each piece. Solid pans trap moisture under the food.
Single layer, no overlap. Same rule as a dehydrator.
Rotate trays top-to-bottom and front-to-back every 1–2 hours. Ovens have hot and cold spots.
Expect longer times. Oven drying typically takes 30–50% longer than a dehydrator at the same temperature, because airflow is weaker. Add hours, not multiples — a 6-hour dehydrator job becomes an 8–9 hour oven job.

What works in the oven: apple slices, fruit leather, tomato slices, jerky (with the 75 °C / 165 °F post-dry oven step — easy to do in the same appliance), kale chips, herbs.

What works poorly in the oven: delicate herbs (most ovens won't go low enough to protect the oils — they end up cooked, not dried), whole blueberries (skins resist drying without long low heat), thick or wet vegetables like zucchini and mushrooms (case-hardening risk).

Dehydrating vegetables in the oven, specifically

Vegetables are the trickiest no-dehydrator category because most are wetter than fruit and most home ovens run hotter than the ideal vegetable temperature.

Blanch first. 2–3 minutes in boiling water (or steam), then plunge into ice water. Same step as for freezing — it stops the enzymes that would otherwise turn dried vegetables bitter and grey in storage.
Slice thin and uniform. 3–5 mm. Thinner than you'd freeze. Thickness variation is the #1 cause of "half the tray is done, half is still wet."
Set the oven as low as it goes, prop the door, and aim for 55–65 °C / 135–150 °F at the food level (an oven thermometer near the tray is worth the $10).
Plan for 8–14 hours on most vegetables. This is an overnight or weekend project, not a weeknight one.
Condition before storage. Cool, then jar loosely and shake daily for a week, watching for condensation. Oven-dried food is more likely to have residual moisture than dehydrator-dried food, so this step matters more.

Air drying

Air drying needs nothing but a dry, ventilated room — no electricity. It only works well for hardy herbs and a few hot peppers; everything else takes too long and risks mould in Canadian summer humidity.

Hardy herbs (rosemary, thyme, sage, oregano, bay): tie stems in small bundles of 5–10 sprigs. Hang upside down inside a paper bag with the open end tied around the stems. The bag catches falling leaves, blocks light, and lets air through. Hang in a dry indoor spot for 1–2 weeks.
Hot peppers (cayenne, chili): thread on cotton string through the stems and hang in a warm, dry, well-ventilated spot. 3–4 weeks. Don't try this with thick-walled peppers — they'll mould before they dry.
Avoid air-drying tender herbs (basil, parsley, cilantro), fruit, and vegetables. Canadian indoor humidity in summer (and outdoor humidity almost everywhere except the Prairies) is too high for the timeframes involved — you'll grow mould before the food dries.

The car-window method (summer only, niche)

A closed car parked in direct sun reaches 60–70 °C internally on a hot Canadian summer day. Spread food on trays on the dashboard or back seat and leave for 6–10 hours. It works for thin fruit slices and herbs, less reliably for anything thicker. Practical only for the occasional batch, and only in July–August when daytime highs sit consistently above 25 °C.

The honest summary: if you find yourself doing more than two oven or car batches a month, the CAD $80–150 entry-level dehydrator pays for itself in electricity and consistency within a season.

The dehydrating process at a high level

Choose ripe, unbruised produce. Damaged spots can carry mould that the dehydrator's low temperature won't kill.
Wash and pat dry.
Pre-treat as needed. Apple slices, banana, pear: brush with lemon-water (60 mL bottled lemon juice in 1 L water) to prevent browning. Blanch most vegetables for 2–3 minutes first (same as for freezing — deactivates enzymes).
Slice uniformly. 5 mm slices dry faster and more evenly than 10 mm. Inconsistent slice thickness means some pieces are done while others are still wet — and the wet ones spoil the batch in storage.
Single layer on trays. No overlap. Airflow needs to reach every piece.
Set the temperature, set the timer, walk away. Check at the halfway point and rotate trays if your unit dries unevenly.
Test for dryness. See the next section — this is the key safety check.
Cool, then condition. Let the dried food cool to room temperature, then "condition" in a sealed jar for a week: shake daily, watch for condensation on the jar walls. If you see moisture, the food wasn't dry enough — dehydrate further before long-term storage.
Store. Airtight containers (glass jars with tight lids or vacuum-seal bags), away from light, in a cool dry place.

How to test for dryness

Fruit: pliable like leather, no moisture when squeezed and torn in half. Apple rings bend without breaking; if they snap they're over-dry (still safe, just brittle).
Vegetables: hard or crisp, depending on the vegetable. Beans and corn rattle. Zucchini chips snap.
Herbs: crumble between your fingers. Stems should snap, not bend.
Jerky: bends and cracks but does not break. No visible moisture beads when you squeeze it.

If the food is sticky, moist, or feels cool to the touch (residual evaporation), it needs more time. "Almost dry" food spoils in storage; "slightly over-dry" is harmless.

Storing dehydrated food and how long it keeps

Drying is only half the job — how you store the food decides whether it lasts months or spoils in weeks. Two steps do most of the work: conditioning, then airtight, dark, cool storage.

Condition first

Even a batch that passed the dryness test can hold pockets of uneven moisture. Conditioning evens them out. Pack the cooled food loosely into a clear glass jar, seal it, and leave it on the counter for about a week — shaking daily so pieces don't clump. If you ever see condensation fog the glass, the moisture wasn't fully gone: return the food to the dehydrator for another hour or two, then condition again. Only move to long-term storage once a week passes with no fogging.

Containers and location

Airtight is non-negotiable. Glass jars with tight lids, or vacuum-seal bags. Every time humid air reaches dried food, shelf life drops.
Dark and cool. Light fades colour and degrades vitamins; heat speeds spoilage. A pantry or cupboard beats a sunny shelf, and a basement or root cellar is better still.
Small jars over one big one. Opening a jar re-exposes everything inside to air. Portion into jars you'll finish within a week or two of opening.
Add a food-grade oxygen absorber to long-term jars — it slows oxidation and helps deter pantry moths.
Label with the date. Dried food doesn't announce its age the way a bulging can does.

Roughly how long it keeps

These are commonly-cited room-temperature ranges for properly dried, airtight-stored food. Cooler storage and vacuum-sealing push them longer; a warm, humid, or frequently-opened jar shortens them.

Dried herbs: 1–3 years. Flavour fades well before they're unsafe, so replace annually for the best taste.
Dried fruit and fruit leather: 6–12 months at room temperature; up to 1–2 years vacuum-sealed or frozen.
Dried vegetables: 6–12 months. Vegetable powders keep longest of all if you store them bone-dry and clump-free.
Jerky: the shortest-lived, because its fat eventually goes rancid. Keep it refrigerated or frozen for anything beyond a few weeks — see the safety steps in our beef jerky guide.

When in doubt, freeze — dehydrated food takes little freezer space and the cold buys months. And trust your senses on the way out of the jar: any off smell, visible mould, or sponginess means compost it, don't taste it. Our guide on telling if preserved food has gone bad covers what to watch for.

Common failures

Mould in the storage jar. The food wasn't dry enough. Condition for a week before sealing long-term and watch for condensation.
Case hardening (hard shell, soft middle). Caused by too-high temperature too early. Start at the bottom of the temperature range and work up if needed.
Browning of light fruit. Apples, pears, bananas oxidize. Lemon-juice pre-treat solves this.
Loss of flavour in herbs. Temperature too high or drying too long. Herbs should be just-dry-enough-to-crumble; over-drying volatilizes the oils.
Jerky safety question. The 75 °C / 165 °F post-dehydration oven step is non-negotiable for safety, even if some US blogs skip it. Health Canada and Bernardin both call for it.

For more of the mistakes that trip up new dehydrators, see our common dehydrating mistakes guide.

What's best for dehydrating

Herbs (parsley, basil, oregano, thyme, sage, rosemary, mint) — fastest, easiest, biggest flavour reward versus store-bought. The gateway dehydrating project.
Apple chips — rings or slices from McIntosh, Cortland, Empire, or mixed windfalls. The fall-staple project.
Dried tomatoes — Roma or San Marzano halves, dehydrated to leather. Note the oil-pack safety rule for storage. Grind the misfits into tomato powder.
Fruit leather — purée fruit, spread on a non-stick tray liner, dry until pliable.
Jerky — beef or bison and venison. Requires the Health Canada post-dehydration oven step at 75 °C.
Mushrooms — slice 3–5 mm; dry until brittle. Reconstitute in hot water for soup, or grind into mushroom powder.
Vegetable chips — kale, zucchini, and sweet potato.
Fruit for snacking — banana chips and blueberries for granola, oatmeal, and trail mix.

Every guide in this method

Sources

Bernardin — Drying / dehydration guidance
Health Canada — Food safety for home preservation (including jerky safety)