Can you dehydrate food in an oven? Oven vs dehydrator
For herbs and the occasional tray of fruit, an oven does the job. For anything regular it is slower, more expensive to run and cannot hold the low temperatures fruit and herbs want.
For herbs and the occasional tray of fruit, an oven does the job. For anything regular it is slower, more expensive to run and cannot hold the low temperatures fruit and herbs want.
The minimum temperature problem
Drying fruit wants 55 to 60 C and herbs want 35 to 40. Most domestic ovens start at 50 C at best, and many at 70 or 100. Above 65 C fruit sugars caramelise at the surface and the piece browns and hardens before the middle dries.
Fan ovens with a proving or low setting come closest. If your oven has no setting below 70 C, the only foods it dries acceptably are things you do not mind cooking slightly, like tomato halves.
Propping the door
Drying needs moist air to leave. A closed oven recirculates it, so you prop the door with a wooden spoon or a folded cloth. That works, and it is also the reason the oven method costs what it costs: you are heating the kitchen for eight hours.
Do not prop a gas oven door, and do not leave any propped oven unattended around children or pets. If your oven has a cooling fan that runs with the door open, check the manual before running it for hours.
Running cost per batch
A dehydrator draws 250 to 700 W. A domestic oven element is 2,000 to 3,000 W and cycles to hold temperature, typically averaging 1,000 to 1,500 W over a long low bake. Over an eight hour batch that is roughly three to six times the electricity for the same food.
Priced at €0.25 per kWh, an eight hour dehydrator batch costs somewhere around €0.60 to €1.10. The same batch in an oven lands nearer €2 to €4. One or two batches a year, that gap is irrelevant. Once a week, the dehydrator pays for itself inside two seasons.
What the oven does acceptably
Herbs, if the setting goes low enough. Semi dried tomatoes. Finishing a batch that came out slightly soft. Toasting and drying breadcrumbs or croutons.
It also works as a one-off test. If you have never dried food, do a tray of apples in the oven before spending anything.
What it cannot do
| Job | Oven verdict |
|---|---|
| Herbs at 35 to 40 C | Only if the oven goes that low, most do not |
| Fruit leather | Poor, the edges set before the middle |
| Jerky | Possible for the heat step, poor for the drying hours |
| Overnight batches | Do not leave a propped oven running unattended |
| A garden glut | Two or three shelves, and the kitchen becomes unusable |
Questions people ask
What temperature in an oven? The lowest it will hold, ideally 50 to 60 C, with the door propped and the fan on if it has one.
Do you have to leave the door open? Yes, otherwise the moisture stays in and the food steams rather than dries.
Is an oven cheaper? Only if you already own one and dry food rarely. Per batch it costs several times more to run.
Safety note. Never prop a gas oven door, and do not run an unattended propped oven overnight. For jerky, follow USDA temperature guidance for the heat step regardless of which appliance dries it.
What this is based on
- Manufacturer specifications for domestic oven minimum temperatures and element ratings
- Dehydrator manufacturer wattage specifications
- National Center for Home Food Preservation, drying fruits and vegetables