This past summer, I built a solar fruit drier to preserve fruit that my housemates and I gathered from neighbors’ yards. The solar drier helps close the circle on my personal campaign to step off the fossil fuel powered food system by re-learning how people used to get their food before the industrial age. I’ve learned that growing or gathering my own food for free — even in an urban environment — is not only possible, it is deeply enjoyable and very educational. When you connect with your own food, you learn about alternative ways to measure time — guided by the sun and the seasons, not clocks and human make-believe. You learn to talk to your neighbors and find ways to cooperate with them, rather than just trying to stay out of each other’s way. You learn about distributing food outside the capitalist market system. And you learn a lot of very tangible do-it-yourself skills. This article provides simple plans for building your own solar fruit drier, and describes why you might want to.
The way we currently live and eat — in a very complex, high-tech, corporate food production and distribution systems totally dependent on fossil fuels — is killing the earth with global warming, soil depletion, ocean dead-zones and poisons. These systems subjugate people to the needs of the market and concentrate power in a few hands while removing most of us from any understanding of how things work. We lack a real voice in deciding how the economy is operated.
How is it that “low-tech” people 100 years ago could grow their own food and live in balance with the earth, but modern people with all our development and learning can’t seem to do the simplest human things — like eating — without damaging our only home’s life support systems?
How is it that with such a high “standard of living” due to all of this industrialization, people are so sad, so lost, so confused, so addicted, so unhealthy? The high-tech modern world hasn’t brought us happiness or meaningful engaged lives equal to the resources it consumes, the cultures it destroys, and the people it dominates. Could it be that most people’s actual level of satisfaction, humanity and engagement was higher before we had all these fancy industrial toys?
I don’t know but I can say that I’ve found a measure of connectedness, meaning, beauty, and calm as I’ve re-joined life’s web as an active participant — rather than merely as a consumer — by growing, gathering, processing, distributing and enjoying home-grown food. This is slow food on the cheap — do-it-yourself slowness, not just another food fad offering expensive products for you to buy after a long day at work.
So back to the solar fruit drier. The main type of food I’ve been able to gather in the Bay Area is fruit. As described in previous Slingshot articles, if you look around your neighborhood, you start to notice lots of fruit trees that aren’t getting harvested — the fruit is just falling on the ground. If you knock on the door, your neighbors are often happy to let you harvest their tree, and you’re building community in the process.
But what you learn as soon as you start gathering fruit is that the biggest problem is having way too much all at once. What to do? Going beyond capitalist ideas of ownership is a good first step — figure out how you can give away the fruit you just gathered. Get on your bike and ride around to friends, infoshops, farmers markets — I like to give free food out at Critical Mass Bike rides. At the end of the day, you’ll still have more than you need, and that is where preserving food comes in.
Drying food is the oldest method of preserving food because it is the easiest. In some climates, you can simply cut up fruit you harvest, spread it out in the sun, and it will dry. But this has a few problems which is why I built a low-tech (but still nifty) indirect/pass-through fruit drier. If you dry fruit right out in the sun, the sun’s rays bleach out some of the vitamins and nutrients in the food. You may have problems with bugs or other critters. If it rains, you’re in trouble. Before this summer, my housemates and I used an electric powered fruit drier that worked well, but I didn’t like the connection with a huge fossil/nuclear powered electricity grid.
I got the basic design for my drier from two excellent articles written by Dennis Scanlin published in Home Power Magazine (#57 and 69) and I made some modifications described here. I built the solar drier to sit on part of the (south facing) front steps of my house. It is built in two parts that unhook for winter storage; the solar collector and the drying box where you put the fruit. (See diagram.)
The idea is that the sun shines on the solar collector (an insulated box with plexiglas on top) and heats piece of black metal window screen inside. The screen gets very hot. Cool air flows into an opening at the bottom of the collector and as it circulates up through the hot window screen, it gets hot. The hot air rises and pulls more cool air into the bottom of the collector creating a steady flow of air upward through the system.
At the top of the collector box, the hot air enters the drying box. It is just an insulated box with a door at the back. You build wood frames and stretch fiberglass window screen over them on which you lay sliced fruit. At the top of the box, there are adjustable vents allowing hot air to escape. If you close the vents, the box will get hotter and if you open them more, the box will get cooler. During the day, hot air moves from the bottom of the box to the top vents, drying the fruit inside.
On an average day, temperatures in the box are 140 – 150 degrees, which is great for drying fruit. If the temperature gets hotter than 150 degrees, it can deplete vitamins from the fruit, so you have to open the vents on top more.
I made the drier mostly from scrap lumber and a $5 scrap of plexiglas from a local recycled building material center (Urban Ore.) I had to spend about $30 on the two types of window screen and a piece of rigid foam insulation that I moved from the lumberyard to my house via bike trailer. The best black metal window screen is from New York Wire. I used old bike inner tubes cut in half to seal around the door on the drier box and between the solar collector box and the piece of plexiglas. The Scanlin article suggested using a special type of solar collector glass but I think anything clear (and cheap) will work just fine. The only error I made building the whole thing was using some duct tape to hold the rigid insulation together inside the drying box. Oops — the drier gets way too hot for duct tape!
The best part of this project is figuring out how to use it. When my housemates and I used the electric fruit drier, you could put the fruit in to dry anytime you wanted. You just flipped a switch and it worked — the fossil fuel use, capitalist labor, eco-destroying technology and centralized economic power all neatly hidden. This, by the way, is the real problem with modern technology — it hides what is really going on and makes things that are actually really, really complex and ecologically troublesome look “easy” and quick to the end user. There is nothing easy for the environment or human workers about using electricity or other forms of technology that tie your daily life to the death-machine.
But I digress. To use a solar fruit drier, you have to fit your schedule around the sun. This is a surprisingly difficult psychological shift. Modern people hate having to adjust their schedule to the earth or the sun. We have been socialized to want instant gratification and to be insulated from how things are. Using a solar drier means you have to wake up a half hour early and cut fruit to put in the drier before work, rather than doing it at night, because the fruit will get all brown and mushy if you cut it and leave it overnight waiting for the next day’s sun.
In the cool and often foggy bay area climate, I’ve found that it usually takes a day and a half to dry fruit and that it dries unevenly. After the first day, I go through the fruit and pick out whatever has dried (usually smaller pieces.) The more uniformly you can slice the fruit, the better. Cutting up fruit to dry it meshes well with using home grown organic fruit since there are always a lot of pieces of fruit with worms or other defects that need to be cut up to be used. I usually grade the fruit when I harvest it — “eating” fruit with no defects goes in the fruit bowl and wormy fruit gets dried.
This year I harvested, moved by bike, and solar dried apples, pears, peaches, apricots, tomatoes, plums and pluots (a cross between plums and apricots).
It isn’t often in the modern world that you get to eat a truly fossil fuel free food product. By fossil fuel free food, I mean food that is grown, harvested, transported, processed, and distributed without burning fossil fuels. For me, that also means food that isn’t bought or sold because the market economy is so soaked in oil. Once capitalism gets a hold of an alternative good or service like organic food, for instance, the real spirit is lost and producers just aim to meet the minimum standard of some legal definition. It is so ironic to think of people buying organic tv dinners at Whole Foods, the world’s biggest and most centralized health food corporation, or buying organic milk shipped from a feedlot in Colorado. Organic?
We need to go beyond the organic label or even farmers’ markets by re-connecting with the food we eat. I recently heard that a study found that the fossil fuel consumed per unit of food by farmers markets was actually more than industrial food because of economies of scale, i.e. lots of pickup trucks going short distances vs. a big semi moving more food longer distances, but for less fuel per unit. I don’t know if this is true — I volunteer at an organic farm that sells at the Berkeley farmers’ market and I’m convinced that the food they raise is better on many levels (psychic, land use, ecological) than Safeway.
To get out of the ecological collapse human society is currently creating, we have to re-think everything. That means re-claiming ancient ways of preserving our food with the sun, not fossil fuels. And it means recognizing that food is what connects us to the earth and to other species, — it isn’t just another business. We are animals on an abundant earth and we are part of the food chain. Gathering, hunting and growing food is an essential human — and an essentially humanizing — act.