Sam writes and asks, “We have a bunch of beefsteak tomatoes that my sister wants dried. We have a gas oven but no dehydrator. What is the best way to do this?”
You can dry or dehydrate foods in the oven and tomatoes do very well when preserved this way. The first thing to do is figure out if you want your oven-dried tomatoes in slices or in sections (i.e., slicing into quarters or eighths).
1. Start by washing the fruit well and discarding any that is over-ripe or bruised.
An easy way to wash it is to put the tomatoes in the sink, fill it with water and add approximately 1/2 cup of vinegar plus the juice of 1/2 lemon per gallon.
2. Drain the fruit well and core it before slicing.
3. Preheat your oven to 200 degrees F.
4. Prep your “drying tray” by placing cooling racks (fine mesh ones work best but the others will still work) on top of cookie sheets.
This will allow maximum air circulation around the tomatoes and help them to dry faster. In case you're interested this is also how I cook bacon in order to avoid bacon grease splatter all over the stovetop [20 minutes at 325].
5. Slice your tomatoes.
If you are going to dry your tomatoes in sections you'll need to pierce the skin in a few places to make sure all of the moisture can get out during the drying process. I find that when dehydrating tomatoes it goes faster and works better if I remove most of the seeds and the pulp. That's a personal choice though, some people like the seeds in it. If you're removing the seeds this is the time to do so.
6. Gently toss them with a little bit of olive oil and then arrange them on the cooling racks. Lightly sprinkle with sea salt or minced herbs if desired.
7. Bake.
This is where it gets a bit tricky. How long to cook them for. Well, that depends. On how thickly they are cut, on how juicy they are, on the ambient humidity, and how dry you want them. If you're looking for serious long-term storage it will probably take at least 8 hours. You want the tomatoes to be very reduced in size, with curled-up edges and almost leathery looking. They need to still be a bit flexible, you don't want to dehydrate them until they are brittle.
In order to use your oven-dried tomatoes, you'll need to rehydrate them for about 20-30 minutes in liquid. You can use either warm water, broth, wine, or even olive oil. These amazing veggie treasures can be used in soups, chopped for salad topping, added to meatloaf, used to create an intense flavor in sauces, the variety of uses is only limited by your palate and your imagination.