We have been making a crude, but good, nutritious and delicious form of fruit leather using our barn's roof and the sun as a giant solar dehydrator. With berry season in full swing and the amount of space allotted for berries in our freezers already past capacity we begin to focus on other preservation methods. One of these is drying or dehydrating the fruit. We do have a small electric dehydrator that could be forced to run non-stop from now well into mid-December. That's not really an option though as it would waste a lot of electricity and be much too hard on the dehydrator that is mostly used to dry morel mushrooms in the very early spring.
Fortunately, as long as the summer provides us with enough sunshine and not too much humidity we can easily dry various fruits and berries right on top of our barn roof. Any sunny spot works great for this, a car roof, the top of one's cold frame, or even an old stump. The important part is to get the product into the sun and off the ground away from, in our case, ants, cats, and small children. The barn roof works great for this as the one side is angled towards the south and gets full sun most of the day.
One of my drying screens full of shallots for next year's sets. We don't dry these in the sun.
The combination of corrugated galvanized metal roofing, slope of the roof, and the sun creates a perfect scenario for drying food. The corrugation provides air spaces under a screen or tray allowing the air to move up the roof carrying away the moisture from under the trays of food. The galvanized metal also gets hot and reflects heat back onto the food. We use old metal pizza pans for the fruit leather and I have screens for drying apples, pears, plums, tomatoes and so on. Right now we are working on drying raspberries.
Once the berries are picked we simply crush them into a puree and spread evenly onto the pans, about a quarter inch thick. Evenly is the key word as any thin spots will dry first, stick and tear holes in the leather when you try to remove it. Now if you want to be fancy, the puree can be strained of seeds. We like it in it's more natural state and leave the seeds in, besides it's a lot less work that way.
After 5-8 hours in the sun, or when the top portion appears dry but before the bottom begins to harden, the fruit needs to be flipped over to finish drying. I use a metal spatula for this and carefully work my way under the fruit folding it over as I go until it can be carefully turned. Another 3 or more hours and it should be ready. Sometimes this process takes two days to complete, one for each side. It all depends upon what you are drying. For example, it always takes me two days to dry raspberries...7 hours on one side and 4 on the other. Once thoroughly dried there should be no moist spots and the leather will hold together quite well, it can then be either frozen or stored in an airtight container, we use old gallon jars for this.
Voilà! Ready to be torn or cut up into smaller pieces for storage. What a great hiking snack this makes.
Properly dried fruit can keep this way for years, if not dried enough it may start to mold.