How to Dehydrate Food in Your Oven

Ensure equipment, surfaces and hands are clean.

Only fresh, good-quality food will give the best results. Wash it, then pat dry with a paper towel.

Prepare the food as though you were cooking it, so you might peel and core an apple, remove the stone from a plum, trim the fat off meat. Then leave them whole, or cut into thin slices or strips.

For foods like apple that tend to go brown, add ½ tbsp of vinegar or lemon juice to 250ml/9fl oz/1 cup of water, then dip the slices as you cut.

Blanch hard fruits or vegetables in a saucepan of boiling water for a few seconds, then refresh in iced water and pat dry.

Fruits like apples, peaches and rhubarb will keep their flavour if you poach them first in a light syrup.

You could marinate meats in olive oil and vinegar, then toss with seasonings before dehydrating.

Put food in a single layer, not overlapping, on a lined baking sheet or a wire rack in the oven (or the racks in your hydrator). Put a drip tray under meat. Items with similar drying times can be mixed on a rack.

Switch on the oven to 45-70°C/115-150°F/gas ¼ or less, depending on the recipe. If your oven doesn’t go below 70°C/150°F/gas ¼, don’t worry. Set it to its lowest temperature but leave the oven door slightly open, enough for the air to circulate and keep a constant temperature.

Turn the tray every 30 minutes or so if you can until the food is completely dry. That will be about 4-5 hours for beetroot (beets), onions and peppers; 6-8 hours for garlic; 8-10 hours for apples, mushrooms and pears; 10-12 hours for apricots, peaches and potatoes.