Make snacks and preserve food with an electric dehydrator.
In times of plenty, a dehydrator is useful for preserving surplus fruit, vegetables, meat and herbs. It can also be used to make delicious, healthy snacks for school lunches and lightweight meals for overnight tramps.
We test dehydrators by drying apple slices, kale, tomatoes and beef.
You can hang food on a line outside or put it on screens to dry in the sun the old-fashioned way. It’s also possible to dehydrate food in an oven, but yours might not have a low-enough temperature setting. The most convenient method is to use an electric dehydrator, with an integrated fan to warm and circulate air over food placed on trays. The air removes excess water from the food, extending its shelf life.
Rectangular dehydrators often have pull-out trays and a fan at the back. This configuration allows for good airflow and even drying. Also, food is less likely to fall on to the electrics.
Round dehydrators usually have stackable mesh trays. Some round models are expandable (you’ll need to buy extra trays). As the height of each tray is fixed, you won’t be able to dry anything “taller” than the tray unless you use a spacer ring to create extra height.
Depending on where the motorised fan is, food can obstruct the airflow. This means you’ll have to rotate the trays at regular intervals to ensure food dries out evenly.
Also, if the fan is placed at the bottom of the unit, you’ll have to take care to ensure food doesn’t fall through the mesh screens and short the circuits.
Size: Dehydrators are bulky (some are bigger than a microwave). They’re also slow (by design), so be aware that part of your benchtop will be out of commission for an extended period.
Capacity: Round dehydrators tend to have less usable surface area, so you might not be able to dry as much as you could with a rectangular model.
Temperature range and settings: Some dehydrators have fixed settings (eg low, medium and high). Others allow you to choose a temperature between 30°C and 70°C, for example.
Trays: These are usually plastic mesh screens (for airflow), but some manufacturers include a flat tray for drying puree or very small pieces of food that would otherwise fall through the regular screen. If you don’t have a puree tray, place a piece of baking paper on top of the mesh tray. Bear in mind that even if the trays are dishwasher safe, they might not fit.
Viewing window or door: Rectangular dehydrators often have a see-through sliding door, making it easy to check what’s going on inside. With round dehydrators, the sides of the stackable trays can obscure the contents. If there is a see-through lid, you’ll be able to monitor the top tray.
Is there a material difference between round and rectangular dehydrators? To see how they stack up in the kitchen, we put them through their paces at our laboratory. Here’s how we do it.
We aim to test brands and models you’re likely to see when you head to the shops, plus some you might not be aware of.
Before we buy anything, we do our research: we visit stores, both online and physical; we talk to experts and consumers; and we ask manufacturers about their range of models. We want to capture new developments in the market and make sure the products we test will be available after we publish our results.
We then compile a list of models and head out to purchase them, just as any consumer would. Where it means we can publish on upcoming models not yet in stores, we will accept samples to test from distributors.
We prepare a variety of foods to test various functions. With all our tests we’re looking for evenly dried food. We also want the dried food to have an intense flavour and smell, attractive appearance (minimal loss of colour) and good texture. We follow the manufacturer’s instructions where possible and check on the food periodically. We rotate the trays, if necessary. With each test, we also do a control batch in a fan-forced oven.
For apple chips we core the apples, then slice them into 1.5mm slices. We place a single layer on each rack, without overlapping the slices. We set the temperature at 60°C or “medium”. Apple chips should have a crisp, crunchy texture, a sweet, concentrated fruit flavour, and minimal losses in colour and size.
Semi-dried tomatoes should be plump and pliable. We cut roma tomatoes into quarters or sixths and place the slices in single layers. The temperature is set at “medium” or between 50°C and 58°C.
With beef jerky, the aim is to dehydrate a food typical of dehydrating, with an importance on food safety to assess the food dehydrator’s ability to dehydrate evenly. We freeze the meat slightly to make slicing easier, then cut it into 5mm-thick slices. We marinate the slices overnight in a soy sauce-based marinade, then place single layers on the racks. We run the dehydrator at about 70°C or “high”. The jerky is ready when there are no red areas when a piece is broken open. It should look cooked and will be firm, not wet. You don’t want the jerky to snap – it should bend with no moisture squeezing out. There should be a concentrated beef flavour.
For kale chips, we place single layers on the racks, on a “medium” temperature between 50°C and 60°C. The result should be crisp, dry kale that rehydrates in the mouth.
Our overall score for dehydrators includes assessments for:
performance (80%, with all four food tests weighted equally)
ease of use (20%, including general ease of use, assembly and storage, ease of operating controls and ease of cleaning.)