Drying food is great for campers and hikers, but home cooks have good reason to use this cooking technique to make oven-dried tomato slices. Why? Simply because they’re awesome in vegetarian sandwiches. Let’s not forget that tomatoes are technically a fruit and their sugar content is quite high. Without moisture, flavors become super concentrated in a similar way raisins do with grapes. After you dry them in the oven, you will experience the tomato’s natural sweetness similar to sun-dried tomatoes.
Aside from the benefit of added flavor, oven-dried tomato slices also contribute to a less messy sandwich. I have a friend who always hated tomatoes in sandwiches because they make everything soggy. I thought about it, and she was kinda right. Tomato juices always invade the other elements, creating a mushy situation and the sandwich doesn’t last long at all. You must eat it right away. This is exactly why I always subconsciously avoided buying pre-made sandwiches with tomatoes at cafés.
A few things to remember
Oven-dried tomato slices are super easy to make, but there are two key things to keep in mind. You have to be really patient; and you must cut them quite a bit thicker than normal. Most fruits are about 90% water, so that’s a lot of moisture to be extracted. The typical ¼” sandwich slices will become paper thin when dried, so you should cut these a bit thicker … about ⅜”. I used the height of my pinky finger as a gauge. Each slice will shrink considerably, so buy more tomatoes than you would think. One large 13″ x 18″ sheet pan fits 4 good sized tomatoes. Also, be patient because this will take at least 3 or 4 hours.
Vine tomatoes should be used for this, as they are praised for their sweetness and size. Roma tomato slices would be too small after drying, and the larger beefsteak tomatoes usually fall short in flavor. If you can get your hands on some beefy heirloom tomatoes, I imagine they would be divine for oven drying as well.
Oven temperature should be as low as possible. Several recipes call for 250 degrees, which I certainly tried. However, my oven could not maintain such a low level of heat and it eventually shut off. So I had to increase the temperature to at least 300 and they did just fine. Definitely play around with the temperature depending on your oven’s capability. In the 90s I had a food dehydrator and that is really the ideal thing to use if you have one. However, I simply don’t have the space to store a bulky machine that I won’t use very often, so be assured that you don’t really NEED one for this.
What you need
- vine tomatoes
- olive oil
- 13″ x 18″ sheet pan with a wire rack
What to do
- Pre-heat oven to 275 degrees.
- Brush your wire rack of your sheet pan with olive oil to prevent sticking.
- Cut your tomatoes crosswise into ⅜” thick slices and arrange them on a wire rack in one layer with none overlapping.
- Place the pan in the oven and let them cook slowly for about 3 hours, rotating the pan 180 degrees after 1 ½ hours. Keep an eye on them as the 3rd hour approaches because some smaller slices will dry out faster if your thickness was inconsistent. Remove each one from the oven as they finish.