Oven-Dried vs. Dehydrator?  Heirloom tomatoes vs. Roma tomatoes vs. whatever-you-have-available tomatoes?

With another frost coming and the day length getting shorter, I decided to go out last night and harvest everything in the tomato tunnel that had any color whatsoever.   Although they won’t develop their sugars any further now (since they’ve been harvested), they will color up over the next week.  The visual of a bright red dried tomato is so much more appealing than pale pink or slightly green tomatoes…and I definitely think the taste of food is enhanced by its visuals, don’t you?

So, on to process.  I have done oven-drying, sun-drying and drying with the food dehydrator and for me, the food dehydrator wins hands down.  Oven drying works, but the tomatoes come out quite dark in color and the texture is more difficult to manage.  They will often become way too brittle.  Here is a quick rundown on process tips for both oven-drying and using the dehydrator:

1. Choose the meatiest tomatoes you can find or you will get a lot of dried tomato skin and they will be much more brittle.  The very best tomato for drying is the Principe Borghese heirloom.  It is a plum-size tomato with a lot of meaty flesh, a lot of bold taste, and just the right size for drying.  Romas and some globe tomatoes are quite meaty and will dry well, but they just don’t have as much taste as the Principe.  Beefsteak tomatoes are usually pretty juicy and are difficult (not impossible) to dry.  Choose those with a high-acid, bold taste.  Now is not the time for the sweet, mild flavor of some tomato varieties.
2. Adapt your slice and dice to the type of tomato you have.  If it is a plum tomato or a cherry, just cut in half and place them sliced side down on your dehydrator tray or your cookie sheet if oven drying.  If it is a globe tomato, slice the tomato thickly and then cut slices in half (these will shrivel to bite-size. 
3. Drizzle with oil and salt…or not.  Many people will oil and salt their tomatoes before drying.  I don’t do either because I sell them at market and people have different tastes and needs when it comes to oil and salt.  For home use, I will add the salt to the dish rather than the tomatoes.
4. Turn on the heat and air.  Dried tomatoes need not only the heat, but also good air circulation.  If drying in an oven, turn the heat on to about 200 degrees and crack open the oven door.  A convection oven works best due to the circulation.  If drying in a food dehydrator, I turn the heat on to 135 degrees for the first 5-10 hours and then decrease it when they have dried to a point where they are almost ready but still a little soft to the touch. 
5. Timing.  This is hugely variable.  It is going to depend on the type of tomatoes you use and the type of heat/air source you are using.  The only thing for sure is that it takes quite a long time.  I frequently leave my dehydrator on overnight and then finish them off at a lower heat for a few hours in the morning.  You just have to keep checking them the first time you do it to see how your heat source works.  Check every hour or two by feeling them.  Two key factors:  they should end up pliable-not brittle, and they should not have any moistness to the flesh (or they will mold later).
6. Remove them in stages from the tray/pan.  The tomatoes are all different (just like us) in terms of ripeness, how you cut them, where they lay on the cookie sheet, etc.  You need to remove the ones that are done (to a countertop to cool) and leave the others to finish.
7. Store.  I store mine in breathable plastic bags.  I know some people will store them in oil in the refrigerator, but my refrigerator is much too full of leftovers, etc. for that and the oil will go rancid if you leave it out.  If you store them in oil, be aware that the oil will get murky in the fridge and them clear up when you get it back to room temp.
8. Use all winter.  Dried tomatoes can be used in so many delicious ways (I’m sure there are many blogs about this!).  Rehydrate them in warm water, toss them in a tomato sauce to slowly rehydrate, cut them up dried and toss in a salad, or munch on them as-is for a great snack. 

Sally Swift, from the Splendid Table’s How to Eat Weekends blog, had a really interesting way of using dried tomatoes.  I haven’t tried it yet, but I plan to very soon.  She said: “If you need great tomato taste ASAP, chop them into pieces and doctor them with a dash of fish sauce. Taste and add sugar, and maybe even a little vinegar to get the high notes. The fish sauce brings a meaty umph and the sugar and vinegar bring out the highs and lows. ”  Yum, sounds good to me.

Cheers ……….Dorothy