Make Dehydrated Tomatoes for Hands-Off, Easy Tomato Preservation – GWC Mag

Dehydrated tomatoes take up little cupboard space, preparing them requires minimal hands-on work and, like other food preservation techniques, dehydration helps prevent food from going bad and going to a landfill where it would emit planet-heating methane gas.

When tomato prices plummet at the farmers’ market in early fall, I buy at least a few 20-pound cases of them to roast, cook down into tomato purée or cook down further into tomato paste or dehydrate. I spend an entire weekend cutting and prepping and cooking and drying pound after pound of tomatoes, wondering why I do this to myself. Later, when I savor summery tomato flavor in winter, I have my answer.

Good tomato varieties to dehydrate

I dehydrate dry-farmed Early Girls but other good contenders include cherry tomatoes, San Marzano tomatoes, Romas or another type of plum tomato. Juicy heirlooms will dehydrate but with their high water content, they require more time and energy.

How to dehydrate tomatoes

To prep tomatoes, wash, pat dry and remove the cores (without removing much flesh). Cut into slices approximately ¼-inch thick. Dehydrate the tomato slices until dry yet pliable or dry and brittle (more on that later).

Oven

Spread the slices on metal cooling racks set on cookie sheets to allow air to circulate around the slices. (This setup negates the need for parchment paper.) Dry the tomatoes at a very low temperature (140°F unless your oven’s lowest temperature is higher). Your tomatoes may dry out in 5 hours or in 8 hours or longer, depending on the tomato type and oven temperature. Check progress after 2 hours and if you have prepared several trays of tomatoes, rotate them in the oven.

To make using the oven worth your while, you may want to fill it to capacity. You could dehydrate apple slices while you’re at it, for example.

Solar dehydrator

Go here for a post on drying tomatoes in one of these. The solar dehydrator I’ve used can reach a temperature of 225°F on a very hot day. Because the temperature of a solar dehydrator will vary, the tomatoes may dry out in 8 hours or you may need and additional day of drying.

Of course, if you have an electric dehydrator, you can use that and likely already know how to dehydrate tomatoes. Dehydrate at 140°F and follow the manufacturer’s instructions.

A good friend of mine has a small air fryer that also dehydrates. No wonder people are obsessed with these!

Car

I use the same cooling rack–baking sheet setup as the oven and place the tomatoes under the rear windshield of the car parked in direct sun on a sunny, hot day (the tomatoes pictured in this post dried on a low 80s Fahrenheit day) and check them every couple of hours. These had a late start (2pm) so they required an additional day in the sun to dry out.

Please note that my old car no longer off-gasses. I also do not hang air fresheners from the mirror (or anywhere else). When you smell fragrance, think phthalates, endocrine disruptors that are detrimental to human health. (I don’t have air fresheners in my home either.)

Check the weather before dehydrating in the car (or solar dehydrator). I dehydrated more tomatoes last Wednesday when the forecast predicted a sunny, 90ish degree day (the heat hit 94°F). This weekend, the temperature dropped so I didn’t buy any tomatoes to dehydrate. If I miss my car-window window of opportunity to dehydrate more, I’ll use the oven later this month.

When are the tomatoes finished dehydrating?

The fruit will shrink in size, feel leathery and lose most of its stickiness. But when it’s done depends.

Chewy

At the chewy point, dehydrated tomatoes taste like candy or fruit leather. Similar to raisins, the interior can be slightly moist when you bite into it, but not so juicy that you can squeeze liquid out. If the tomatoes contain too much moisture, they can become moldy in storage. So you need to strike the right balance. (I’ll cover a trick on finding that balance down below.)

Tomato powder

If you want to grind the tomatoes to make tomato powder, you’ll need to dehydrate them until they become brittle enough to snap in half. Chewy tomatoes will gum up your spice mill or blender when you try to grind them. It won’t work (I’ve tried it).

To use the powder, add a small amount of water to it to make tomato paste. Add more to make tomato sauce. Or add tomato powder to dishes that could use an infusion of tomato flavor.

Storing and conditioning dehydrated tomatoes

Conditioning dehydrated tomatoes will help prevent them from spoiling.

To condition, allow the dehydrated tomato slices to completely cool. Pack them loosely in glass jars and store in the cupboard or on the kitchen counter. For the first week, carefully check the jars for condensation daily. If you notice any moisture, return the tomatoes to the oven to dehydrate further. Once completely dehydrated, the tomatoes will keep for up to a year, depending on your kitchen environment.

You can also refrigerator or freeze the dehydrated tomatoes. One of the beauties of dehydrated food is the ability to store it without requiring energy. But if you worry the tomatoes haven’t completely dried or you live in a very humid climate, the refrigerator or freezer acts like an insurance policy.

What to do with dehydrated tomatoes

• Reconstitute into sauces and soups to add flavor. I reconstitute these directly into what I’m cooking, such as a pot of pizza sauce. Purée the sauce after the tomatoes have plumped up.
• Chop them up and add to baking. I have to try them in these sourdough biscuits. I think that would taste amazing as would a loaf of sourdough bread. (I’d soak them first in a small amount of water and use that water in the bread dough.)
• Make tomato pesto. Essentially, you swap out basil in a classic pesto recipe for the tomatoes. This recipe looks good. You’ll have to marinate the dried tomatoes in olive oil first.
• Use as a topping. Marinate them in olive oil and top pizzas or toss in salads.
• Eat them straight out of the jar. They are hard to resist.

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