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Preserving Tomatoes: Dehydrating

by Don Janssen, UNL Extension Educator

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You carefully planned, and planted, and watered, and fertilized your seedlings tomatoes, and watched and waited anxiously as they grew big and sturdy. Finally that first fruit changed from green to red, and you savored that wonderful first tomato of the season.

But now you have more than you can use fresh. What do you do with all of them before they go bad? After giving away or donating as many as you can and freezing or canning some you may want to consider dehydrating them.

Drying removes the moisture from foods, inhibiting the growth of microorganisms. To be properly preserved, the food must dry slowly, from the inside out. If the temperature is too high the outside will cook before all the moisture has escaped from the inside, and the food will later mold or rot. To be successful, there needs to be the proper environmental conditions of temperature, air flow, and humidity.

Tomatoes can be dried in your oven, if you can set it to a very low temperature (150 degrees F). In an electric oven set at 200 degrees-225 degrees F the results will be somewhere between a sun-dried and a roasted flavor. Put the prepared tomatoes on wire racks or foil-lined cookie sheets, leaving room for heat to circulate between the pieces, and put the racks in the warm oven. Rotate the racks occasionally and leave the door propped open a bit to allow the moisture to escape. It will take 9 to 24 hours to dry the tomatoes. Check them often to make sure they don't get too dry.

A home dehydrator is an easier way to dry foods. These electric appliances are engineered to create a uniform environment to optimize drying time. A circulating fan is essential to evaporate the moisture from the food before it molds. When using a dehydrator, follow the manufacturer's instructions and recommendations for drying temperatures and times. There are numerous makes and models of home dehydrators, in round or rectangular designs; some have a fixed number of trays, others are expandable; and they come in a range of prices.

Regardless of how you dry your tomatoes, the best varieties of tomatoes to use are high-solid cultivars. You can use beefsteak or other types, but they will take longer to dry because of their high moisture content.

(This resource was added September 2007 and appeared in the Lincoln Journal Star Newspaper Sunday edition. For information on reproducing this article or using any photographs or graphics, read the Terms of Use statement)

University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office

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