By Joanna Bastian
Two years ago this week our garden was over-producing and there was no way to preserve it all, due to a series of unfortunate events — namely, hell and high water — that left us without power or running water for eight weeks of 2014. The garden decided to ripen every single fruit and vegetable all at once. We were drowning in bounty with no means to preserve it, so most of it was either given away, or churned back into the soil for compost.
So imagine my interest when Katie Haven of McFarland Creek Lamb Ranch posted a photo on the ranch’s Facebook page of a solar dehydrator with the caption, “Just finished my new solar dehydrator. High overcast and it’s 130 degrees inside! Can’t wait to start drying the 20 lbs of cherries I just picked.” Compact and lightweight, the solar dehydrator looked easy to assemble and even easier to operate.
I stopped by during a summer rainstorm when Katie and her friend’s son, Jackson Vanfleet-Brown, took a break from chores to wait out the rain. We chatted around her kitchen table while in her garden sunflowers and hollyhocks acquiesced to stormy winds and thick droplets of rain.
Thumbing through The Solar Food Dryer by Eben Fodor, Katie spoke about why she wanted to build her own: “I like the idea of minimizing electrical use, and I want to dry cherries and apricots.” The book contains detailed assembly instructions for an efficient and highly cost-effective design for a simple, lightweight box that is used to preserve homegrown food off the grid.
Katie and her friend’s son spent a weekend assembling the solar dehydrator from scrap lumber leftover after the rebuild of the McFarland Creek Lamb Ranch barn, which had succumbed to the Carlton Complex fires in 2014.
The food dryer is made from common materials, locally available here in the valley: plywood, 2x4s, ¾-inch trim, sheet metal, flat black spray paint, and glass and screens cut to order from Methow Valley Lumber.
The top of the wooden box is angled with a sealed glass cover. A back door is used to access the inside of the box, where removable food-drying screens slide above a piece of sheet metal, painted flat black. The black metal absorbs solar heat and transmits it to the air flow surrounding the food-drying trays.
The solar food dryer works with natural convection. Warm air inside the box rises and exits through small circular vents near the top of the box, creating a vacuum which draws cool air in through the bottom vents. The cool air is warmed as it flows below the black metal panel, and the now warm air rises around the food-drying screen above. The food is dried using this natural convection of efficient hot air flow.
A small thermometer tracks the internal temperature of the box, which can reach an astounding 160 degrees Fahrenheit on a triple-digit day. Optimum drying temperature is between 110 degrees and 140 degrees Fahrenheit. To cool the internal temperature of the box, airflow can be increased by opening another vent on the back, near the top of the box.
To date, Katie has put up five quarts of dried cherries, and was in the process of drying apricots last weekend. “The cherries took about two days to dry, apricots took about three days,” she explained. Later this summer Katie will use the solar dehydrator to process tomatoes, apples, pears and herbs.
The solar food dehydrator looks like a fun weekend project and a wise investment. No electrical power needed, and no noisy fans. Just fill it up with produce and let the sunlight and natural convection do the rest of the work. More information can be found at www.solarfooddryer.com.