Dehydrating Tomatoes, Making Your Own Sun Dried Tomatoes
  • X pounds of Plum, San Marzano, or Roma tomatoes
  1. First, select your tomatoes. They shrink quite a bit (up to 90%), so bear that in mind when you get started-- make sure you have enough tomatoes to make it worth your time! You can use any kind of tomato, but the more watery varieties will take longer to dry and make more of a mess. The paste varieties (e.g., Roma, San Marzano) are ideally suited for this. If possible, grow them yourself. It will be hard to find anything better. If that isn't an available option, try to find a local source using sustainable agricultural practices. You're going to be eating these, and they're going to be much healthier if they're not sprayed with pesticides and other chemicals.
  2. Wash your tomatoes in water (no soap, please). I like to use a produce scrub brush to remove any dirt from the surfaces. Pat them dry gently with a towel (don't go crazy, you're going to be drying them with heat anyway). If you're using smaller paste tomatoes, cut them into halves or quarters depending on the size of the tomato and the size you'd like your pieces to be. Larger sections will take longer to dry. If you're using very large tomatoes, you may need to divide them into smaller pieces. Remove the stems and any parts that look like anything you wouldn't want to eat. You can peel the skins (by dropping the tomatoes into boiling water till the skins crack and then shocking them in ice water - they'll peel right off) and remove the seeds as well, but this is not necessary and may detract from the flavor. However, if you're using a more watery, slicing variety of tomato, you may want to scoop out some of the water and seeds to hasten the drying process.
  3. Now for the drying. There are a number of ways to dry your tomatoes. Since laying them out in your yard is unlikely to work, you will need an alternative heat source. Some people have dried tomatoes on the dashboards of their car on a hot summer day. This may be fine if you want your car to smell like dried tomatoes and you don't plan on driving anywhere for a day or two. I wouldn't generally recommend this technique, but if that's the way you choose to live your life...
  4. You can use your oven set to 150 degrees or the lowest setting attainable. If you have drying racks, put the slices of tomatoes on the racks to allow the heat and air to circulate thoroughly around the tomato slices. You can use sheet pans or cookie sheets, but you will need to stir the tomatoes periodically so they can dry evenly, and they will be more prone to sticking. Sprinkle the slices with sea salt or kosher salt. You can also sprinkle them with herbs if you like (basil or oregano, for example), but I prefer to season mine in herb-infused olive oil after they have completely dried. The tomatoes will be dried in 10-20 hours typically, but this will depend on the water content of the tomatoes, the size of your slices, your oven, and how dry you want them. You'll want to keep a close eye on them. They should be deep red and leathery, flexible but not brittle. Usually they'll be about a fourth of the size of what you started from. You can shorten the cooking time by cranking the heat up higher (up to 200), but this may over dry the tomatoes and you'll risk ruining the batch if you're not watching carefully.
  5. If you don't feel like hijacking your oven for an entire day, a food dehydrator is a great option. The fenestrated trays allow even heat and air circulation around the tomatoes. The trays stack vertically so you can pack a lot of tomatoes in a small space. The unit I have came with 5 trays, but will accommodate up to 12, and its smaller size makes for more efficient heating than the oven. Excellent dehydrators are available at reasonable prices from a number of retailers. The one depicted here costs about $60, but good models can be found in the $30 to $40 range, or you can spend a couple hundred dollars if you're going into the sun dried tomato wholesale business. It can also be used for dehydrating other fruits and vegetables, herbs, even jerky. Just space the tomato slices out on the tray. They can be close but you don't want them touching each other. Sprinkle with salt as above, and set the temperature between 135 and 145 degrees. Check them towards the finish, they are typically done after 8 - 12 hours.
  6. After removing from your oven or food dehydrator, they are ready for immediate use or storage in your freezer. I like to cool them on a sheet pan in the freezer for about an hour to harden them before sealing them in a vacuum sealer. The vacuum sealer removes most of the air, allowing the tomatoes to keep their color and flavor for many, many months. If you don't have a vacuum sealer, you can use a ziploc bag, first pressing the air out with your hands, and then sucking as much air out as you can through a straw before sealing completely. While I wouldn't recommend purchasing a vacuum sealer just for dried tomatoes, it is a good investment for prolonging the freshness of many foods by months. I use mine all the time to preserve fruits, vegetables, meats, bread, and salumi. And it will extend the life of your sun dried tomatoes considerably over the ziploc method. The dried tomatoes can reabsorb moisture if the air and water are not removed well, and then they will grow mold and spoil. You can also store them tightly sealed in the fridge, but they'll only keep for a few weeks in there.
Recipe by - Italian Food Recipes and Lifestyle at