Introduction: Microwave Dried Tomatoes

Dried tomatoes are delicious!

I have always loved that sweet and salty taste. The idea is to remove most of the water content of the tomato and it is done both by using salt and sugar (osmotic pressure) and by heating the tomatoes (evaporation). The oldest way of preparing dried tomatoes is by using direct sunlight in a process that lasts between 4-10 days, but the most common method of drying the tomatoes is by placing them in a low temperature oven or dehydrator for a few hours.

Initially the idea of removing around 90% of the tomato humidity was for preservation. By having low moisture, condiments and oil, the ripened tomatoes will last much longer without deteriorating while also acquiring distinct flavor. With modern preservation and canning technics being able to preserve tomatoes without changing its flavor, the dried tomatoes have been around due to their distinct and awesome taste. It is also noteworthy that this process maintains the same nutritional level of the original tomato and is pretty healthy!

Since drying with an oven takes so long, this instructable will introduce the usage of a microwave to reduce the moisture of our tomatoes faster, reducing our prep time to around 30 minutes and giving us an amazing product. In just a few hours you should have your own dried tomatoes to munch away! Also, where I live tomatoes are pretty cheap while dried tomatoes are quite expensive so this will save good money :)

Step 1: Ingredients

The ingredients are very simple and easy to find in your local market.

  • Ripe tomatoes
  • Salt
  • Sugar
  • Olive oil
  • Garlic*
  • Basil*

* These are not obligatory but I do use them and they also provide a great flavouring.

The tomatoes i got from the farmer's market for around $0,25 per kg ($0,11/lb). These were the cheaper ones since they were almost over ripened and kinda small, a bargain.

I've used brown raw sugar also bought in the farmer's market in bulk for around $3,3 per kg($1,5/lb). You can use regular granulated sugar which will result in a more "standard" taste. Using brown sugar has that kind of syrup taste that makes an awesome and special product.

I've used curing salt which has sodium nitrate and nitrite in it. These nitrates will inhibit the growth of some harmful bacteria, but for this recipe it is by no means necessary. You will get the same result by using regular or kosher salt. There is virtually no chance of these bacteria growing in this recipe, it is just a whim of mine.

You should use a good olive oil since you will eat a lot of it directly and thus would be the healthiest option. You can use any oil of your choosing though, even cooking oil for that matter, it will still taste good!

The garlic I use is just regular garlic that is pre-diced and made into a preserve, ready to use. The basil is freshly cut from my garden.

This is just a "regular" plain recipe. Feel free to experiment and use any other condiments of your choosing. I've already made some batches using paprika and peppers and it works amazingly.

PS: Since I live in Brazil all the prices shown here were converted to US dollars. It might not be compatible with where you live.

Step 2: Preparing the Tomatoes

This is a simples step.

Cut the tomatoes in half lengthwise (from top to bottom) as shown in the pictures.

Clean the insides of the tomato, removing the seeds and goo. Remove as much liquid as you can here. Don't forget to scrape inside those flaps as some tomatoes should have a few hidden seed and moisture in them. For this I use the most trustworthy tool available, my fingers.

If you want you can save the seeds and liquid, personally I throw them out, can't think of a noble usage. In case you have one, please let me know!

Lay them in a flat surface side by side and let's prepare the seasoning.

Step 3: Seasoning

For this step I've used a scale and once again, it is totally NOT necessary.

I bought around 1,5 kg (3,31 lbs) of tomatoes. I like to make a mixture with around 15% of the tomato weight in seasoning, which sums up around 225 g (0,5 lb) in this specific situation. The mixture should be 2 parts sugar for each part of salt. You can also make it roughly by the number of tomatoes. For 6 tomatoes (whole, not halves) you should use 2 spoons of sugar and 1 spoon of salt. Just adapt the amounts for the number of tomatoes you're using.

The basil and garlic will join in later. If you are using any other powdered condiment this would be the time to mix it in.

Just mix all the powders together and sprinkle them on top of your tomatoes, skin side down. Be really generous in this is step, I've poured the whole mixture on the tomatoes. They will absorb a lot of the powder, don't worry. In the picture you can already see some tomatoes forming little pools in them due to the absorption.

Time for the next step!

Step 4: First Extraction

After sprinkling the mixture on the tomatoes place them with the skin side up for our first drainage. Ideally you would place them in a grate or mesh so the liquid quem drip away but since I don't have anything like that I've just placed them in a tray and made an angle in it so the liquid would slide down. The point of using a mesh is to keep our tomatoes out of this liquid. Leave them to drain for around 30 minutes.

After 30 minutes you will see a lot of liquid forming. This happens because the concentration of salt and sugar inside the tomato is lesser than the ones outside (because of our coating). This results in the water inside the tomate being brought trying to equalize the concentrations and consequently being dragged out of the tomato. Some seasoning also ends up getting inside our tomato's cells.

Drain out all the liquid. Once again I discard this liquid due to a lack of usage. It tastes salty, sweet and tomato-ish.

You can skip this step, but all this liquid extracted here will them be extracted in the microwave step, which will then result in a few more rounds of microwaving and drying.

I've used the microwave dish directly for the next step, but you can use any other refractory bowl or plate of your liking. Cover the plate with paper towel (for my 20 L [5,3 gallons] dish I use 3 towels) and place the drained tomatoes skin side up on top of the towels.

Step 5: Microwaving

Now we will do a few rounds of microwaving. We can't do all in a single heating both because we need to switch the towels in order to remove the moisture and because we don't want to cook the tomatoes or they will become hardened and chewy, jerky-like.

Place the tomatoes in the microwave and let it cook for 10 minutes in maximum power. After the 10 minutes grab a fork and gently push/smash the tomatoes in order to squish some more water out into the paper. The result is in the first picture. The tomatoes are still whole, specially the bigger ones. This first round releases a lot of water and will drench the towels a lot! If you overcrowd the plate like I did you may have a few spills, nothing critical. The idea is to force out all the tomato's humidity into the paper towels by using heat to evaporate the water without cooking the tomato, that's why it is critical that the skin side is up in this step once the moisture comes trough the cut open end.

Remove the tomatoes with a fork and then throw out the drenched towels. Clean and dry your plate, place some new paper towels and rearrange the tomatoes on top of the towels once again. Microwave the tomatoes for another 6 minutes.

At this point I like to sprinkle a little bit of seasoning once again into my tomatoes because a lote of the seasoning has been drained with the water. The mixture is still the same but this time around don'tbe as generous with the coating. Just give them a little sprinkle, show them some love. Of course if you like some more intense flavor, go ahead and season it as you like. This is step is not necessary, if you don't season a second time at all your tomate will be delicious as well. Feel free to experiment.

After the 6 minutes replace the paper towels once again and microwave for another 5 minutes. Change the towels one last time and microwave for another 5 minutes. This time around you should see that the tomatoes have reduced in size and the towel in between them should have quite a few dry spots. It will also start to smell really good. This is the ideal point (at least for me) in which the tomatoes are really tasty and tender.

The pictures are in order for each cycle.

Depending on your microwave the times and number of cycles may vary a little. Find your ideal timing!

Although the tomatoes might look squishy and gooey, specially during 2nd and 3rd cycles, you should be able to grab them whole easily with a fork, they won't fall apart!

Step 6: Final Assembly

The final assembly is the last seasoning and preparation for our preserve.

You can add any other seasoning you want to in this step. You can add nothing at all, just tomatoes and olive oil will work perfectly. I lie to use just garlic and basil because it gives a nice herbal flavor but it won't interfere with the tomato's taste. The residual oil once there is no more tomatoes will also be amazing to use later as dressing or cooking.

Cover the bottom of your recipient with some olive oil and make a layer of tomatoes. Then make a layer of garlic followed up by a layer of basil. Fill the height with oil. Start over again with another layer of tomatoes and repeat until you finish them all. The pictures show that layering sequence.

Although it is already done and good for eating, it is preferable to give it one or two days to settle and incorporate all the flavors into the tomato. It is good when ready, it is a lot better after 2 days in the fridge.

It is reallyimportant that you always keep your tomatoes covered with oil. If you let the tomato out of the oil it may dry up, oxidize or start to rotten. As long as it is fully covered it should last really long. Keeping it in the fridge and/or locked up tight might give you a year's worth of shelf life but I doubt it will last long given how good it is.

Since we take most of the tomato's weight out in water it should yield a relatively light end product. My 1,5 kg ended up at around 250 g in dry weight.

Hope you like it :) Enjoy!

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