Drying produce in the sun is the oldest method known to man for preserving food products. Our earliest ancestors quickly learned that, by drying the food, they could save the food for later use, increasing their chances of survival. These foods included berries, vegetables, fruits, meat and fish.
To dry your produce outdoors in the sunshine, you must first find a spot that is away from where dust is stirred up in an effort to keep the produce from picking up dust and/or pollen.
You should choose a day that is low in humidity and high ambient temperatures ranging in the high 90's F. As it will take several days, even in the most optimum weather, be sure that rain is not forecast for at least three days, hopefully longer, if you are drying fleshy produce such as peaches or plums.
1. Almost all produce to be dried in the sun should be pre-treated with one of the natural pre-treatments to help retain the colour of the produce. Prepare the food to be dried by slicing or chopping (herbs) into uniform pieces. This will assure that most of the produce is dried at the same time.
2. Place the prepared produce onto the drying trays in a single layer, making sure that there is enough room between each piece of produce to assure proper air flow. It is best not to stack the trays as it slows down the drying process for the produce on the lower trays out of the sun. But, if you must, please make sure that there is at least 6 inches between each layer of trays to assure proper air filtration, and, that you rotate the trays each day, placing the bottom tray on the top to expose it to the sun next, then the next day, repeat, moving the bottom tray to the top. Stacking the trays will slow the drying process considerably as the bottom trays out of the sun will need to be moved into the sun. If you have a sunny, white wall on the south side of your home, setting the trays there will add reflective heat to help speed the drying process.
3. Cover loosely with cheesecloth. This keeps dust off of the produce and protects it somewhat from insects which might be drawn to the sweet aroma of, say, drying apples.
4. Place the trays in the full sun. Do not place the trays directly on the ground. Elevate the trays at least one foot above the ground surface.
5. Make sure to turn each piece of produce each day to help make sure that it dries evenly. Check to make sure that no mold or fungus is starting to grow, and, if so, discard immediately.
6. If you cannot move the trays indoors at night, the trays will need to be covered with a layer of plastic or a tarp to protect it from an unexpected rain or night critters such as raccoons. It is ideal to bring the trays indoors, but, I realize that not everyone has the space. A covered porch or dry, clean garage will suffice, for the night, but remember to place the trays back out in the sun the next morning. Remove the plastic covering early in the morning, after the rain has stopped, before the sun hits the trays to avoid even more moisture build-up under the plastic.
7. Under ideal circumstances, the produce should be dry after three or four days, depending on the weather conditions and the size of the produce to be dried. If it rains during the process, it is best to either bring the trays indoors, or, finish drying the produce in your kitchen oven. If this is necessary, transfer the food products onto metal trays (such as cookie sheets) lined with parchment paper. Exposure to the metal will discolour some fruits and vegetables, so it is always better to line the metal trays. The parchment paper has been designed to withstand lower temperatures in the oven, so, unless you have set your oven temperature too high, the paper will not burn at 170 degrees F. Do not dry more than three trays in your oven at a time and make sure that there is at least three inches between the trays and around the sides, top, and, bottom of the oven to allow for proper air circulation.
If you are lucky enough to have a convection oven, the process will speed up considerably, as convection ovens have a fan to circulate the hot air around the trays. Set the temperature to the lowest setting and pre-heat before adding the trays of produce. Check the produce and turn it every half hour or so, and, as it dries, check it even more frequently to make sure that the drying is thorough.
Herbs gathered into small bundles can be hung from small, portable racks, which are easily moved in the event of rainy weather. This one is inexpensive and readily available in many shops. I recommend labeling each bundle with a small tag, which can be re-used next season. Many herbs such as the mints need to be identified according to their scent or variety before they are dried.