Published September 1, 1996.
Surprisingly, the best technique does not use the lowest oven temperature, but it does call for seeding the tomatoes.
As the wave of Italian cooking has swept over America, sun-dried tomatoes have become a staple in many kitchens. However, most cooks don't stock them in the pantry as consistently as other staples. This is largely due to their cost, which can range from expensive to exorbitant. Although the original version of these flavorful, partially desiccated tomatoes was truly dried in the sun, these days most commercially dried tomatoes are prepared in dehydrators.
We wanted to see if tomatoes could "sun"-dried in a home oven, eliminating the need for the home cook to buy dried tomatoes or to purchase an expensive dehydrator.
Slicing the tomatoes in half lengthwise before coring them proved useful, as did scooping out all the seeds and gelatinous matter with a teaspoon. Piercing the skin with the tip of a sharp paring knife also yielded good results. In the oven, the tomatoes dried most evenly on a wire rack placed on a foil-lined tray to catch any juices,. This method allowed for maximum air flow, a nod toward the type of drying environment found in a dehydrator. We also found that a moderate oven temperature of 200 degrees worked better than the low temperatures found in many cookbooks.list of recipes