Farm Focus: USDA Dried Fruit Trial

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Farming and science go hand-in-hand so we're always eager to collaborate with research scientists to learn out to improve our practices. Our most recent project is in collaboration with the USDA. They are interested in testing out commercial application of the Dehytray, tray designed by a Perdue University professor for small-scale farmers in Africa to preserve food through sun drying. Since we already have a fruit sun drying program we were eager to help out and see how process compares to ours and learn if/how we could improve our system. 

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In order to compare the trial results let's review how we currently sun dry our delicious stone fruit! Our process is a simple one and is probably similar to how fruit has been dried since humans figured out it was a safe way to preserve fresh food. We simply slice fruit around the pit and lay it out skin side down on elevated mesh racks in the sun. Pretty straightforward, right? Our fruit gets lots of wonderful California sunshine and ventilation which dehydrates them perfectly, concentrating flavor into soft chewy dried fruit. Generally speaking, this process takes about a week, depending on the type of fruit and weather.

The Dehytray’s goal is to speed up this process by placing the fruit in a black plastic tray with a mesh bottom and a clear lid which acts to trap in heat, almost like a greenhouse, to dry out the produce more quickly. Originally designed to help subsistence farmers in Africa who need to preserve food to eat for the dry season these trays can be used for anything from okra, grains or fruit.

The four trials we've done so far have consisted of three batches of the same fruit, two in Dehytrays and one control batch on our traditional rack. Fruit is sliced as usual and weighed so we can compare moisture loss throughout the trial. One Dehytray is on the ground over a blue tarp and angeled to be south facing on some bricks to match what the USDA’s team is doing in Albany. The second Dehytray is elevated on our drying tables along with our traditional Frog Hollow control batch. All three batches of fruit have been weighed every day at 9:45 am and 1:15 pm in our makeshift laboratory. The laboratory is actually a pump station that is a very popular home for Black Widows spiders which makes the weighing process even more exciting. But don’t worry, Rachel has a handy “cobweb stick” to gently relocate spiders out of the entrance!  Weather data is downloaded from the weather station Abel set up on the roof so that it can be compared to the simultaneous trials happening on the roof of USDA's office in Albany. We expect there to be significant variation since they have lower temperatures and more fog than Brentwood.


As Becky mentioned in this week’s note, our traditional open mesh rack has been finishing before the Dehytray so we know we’re doing something right! Another key factor in comparing the two processes will be taste and texture. While looking at the control fruit we noticed it looks much stickier than the Dehytray fruit, which looks dryer on the surface and puffier. It will be interesting to compare the final products!

Be sure to catch our seasonal dried fruit while you can! Just visit the CSA member store to add on to your next order.