004 Egg Ethics, Solar Food Dryers and a Question about Earth Ovens

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On episode four of the Root Simple Podcast Kelly and Erik discuss the tricky ethics of eggs and mayonnaise, what kind of solar food dryer is the best and we answer a question from Ed about earth ovens.

Plans for the Appalachian Solar Food Dryer can be found in an article on Mother Earth News.

We have a detailed post on how we built our adobe oven here.

If you want to leave a question you can call (213) 537-2591 or send an email to [email protected].

The theme music is by Dr. Frankenstein. Additional music by Rho.

A downloadable version of this podcast is here. You can subscribe to our podcast in the iTunes store. Note that it takes a few hours for the new episode to show up in iTunes.

What’s the Best Solar Food Dryer?

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Appalachian Food Dryer. Image: Mother Earth News.

Dehydration is a great way to put up food. Second to freezing, it’s the best way to persevere nutrition without adding sugar or salt. And if you use the power of the sun, you won’t need to spend any money on electricity.

In a desert climate you can just put your food out on screened trays. But just a bit of humidity in the air makes this approach risky. Food can spoil before enough moisture is removed. That’s why you should build a solar food dryer.

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Brace Direct Food Dryer. Image: FAO.

There are two basic designs for solar food dryers: direct and indirect. Direct dryers are just a box with a piece of glass on the top. Indirect dryers use a box to collect the heat of the sun and then, thanks to the fact that hot air rises, take that heat up into an enclosed box that contains the food you want to dry.

The Poistk Dryer

The Poisson Indirect Dryer. Image: Mother Earth News.

Which design works best? Dennis Scanlin, Coordinator of the Appropriate Technology Program and Professor of Technology at Appalachian State University in Boone, North Carolina has been studying solar food dryer technology for decades.  According to Scanlin, indirect drying is the way to go. Scanlin tested three dryers, the Appalachian Solar Food Dryer (an indirect dryer that he invented) against a direct dryer developed by the Brace Research Institute and the Poisson indirect dryer. In an article in Permaculture Activist, “Evaluating Solar Food Dryers: Stocking Up with Solar Power,” Scanlin says,

The Appalachian indirect dryer produced higher temperatures than the other two dryers and also removed more moisture from the tomatoes drying inside each day. In one test, the Appalachian dryer removed 32 oz. (0.95 L) of water during ta day, while the Brace direct dryer removed only 20 oz/ (0.59 L), and the Poisson dryer only 15 oz. (0.44 L). The Appalachian dryer was able to remove as much as 3.73 lb. (1.69 kg) of water in a single sunny day from tomatoes drying inside.

Scanlin also notes that direct dryers degrade the quality of the food and possibly nutritional value due to direct UV exposure.

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Our Appalachian Food Dryer, badly in need of a paint job.

We built a Appalachian Dryer several years ago and it works great. You do need to remember to bring in the food at night to prevent rehydration and spoilage (for some reason I often flake out and forget to bring in the food). For awhile I had an electric Excalibur Dehydrator on loan and it’s a lot more convenient. But, of course, it uses electricity and makes a lot of noise.

Since I built my Appalachian Dryer Scanlin has decided that it’s not necessary to use insulation. This makes the project even simpler. For just around $200 worth of materials you can easily make an Appalachian Dryer out of plywood nails and screws.

You can find plans for Scanlin’s dryer here.

Journal of the New Alchemists

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“Six-Pack” Backyard Solar Greenhouse, 1975. Image: Journal of the New Alchemy.

After reading an article by Paul Ehrlich, “Eco-Catastrophe!,” Nancy Todd turned to her husband John and said, “We must do something.” The year was 1969 and the Todds along with Bill McLarney went on to found the New Alchemy Institute.

History repeats itself. What the New Alchemists did, in response to the 1970s era energy crisis and political instability, sounds a lot like what people have been up to since the 2008 economic bubble: aquaculture, organic gardening, earth building, market gardens, no-till agriculture, old timey music, wind power, four season growing, permaculture, non-hierarchical leadership and goats. Only the 1980s era of appropriate technology amnesia separates current efforts from the work of the New Alchemists.

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Aquaponic system. Image: Journal of the New Alchemy.

By accident I discovered the Journal of the New Alchemists deep in the closed stacks of the Los Angeles Central Library. As revealed by their journal, what distinguishes the New Alchemists from other efforts of the time is the Todd’s science background. The Journal has a refreshing research-based approach to its subject matter. The period I reviewed (their last decade of publication) covers mostly their agricultural experiments, but occasionally dips into urban planning and other subjects.

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Biodome. Image: Journal of the New Alchemy.

It’s interesting to look back at their work to see what ideas went mainstream and what faded away. What didn’t stick is what Nassim Taleb would call “top-down” approaches to design epitomized by the 70s fixation on geodesic domes and self contained ecosystems (though we’re starting to see a resurgence of the latter via a renewed interest in aquaponics). The more bottom-up work of refining conventional organic agriculture through no-till farming and integrated pest management had more long lasting influence. One could make a good argument that you need the domes and aquaculture schemes to inspire people to work on the more prosaic stuff. But another criticism of the appropriate technology movement of the 70s is that it focused on technology rather than social and political problems (see economist Richard S. Eckaus article “Appropriate Technology: The Movement Has Only A Few Clothes On“). We may be in the midst of repeating that mistake.

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Aquaponic system. Image: Journal of the New Alchemy.

One does not need to wander the closed stacks of the library to find the amazing Journal of the New Alchemy. Thanks to the internet you can download the New Alchemist’s publications as pdfs. Aquaponic enthusiasts will find much information. The Journals are a fascinating read and gave me a great deal of respect for the founders of the New Alchemy and their many contributors (one issue features a young Gary Paul Nabhan). They went far beyond talking the talk and walked the walk. They did something.

Dry Climate Vegetables

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Here in Arrakis, I mean California, we’re in the midst of a terrible drought. And unfortunately, most of the seeds we buy for our vegetable gardens are adapted to require lots of water. One solution is to find veggies that have reseeded accidentally without supplemental irrigation. Here’s a short list of reseeding rogue veggies from our garden that have thrived with just the small burst of rain we got last month.

Continue reading…

What the Internet Will Look Like After the Zombie Apocalypse

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Enterprising amateur radio operators in Texas, over the past several years, have created a wireless high speed data network, called HSMM-MESH or Broadband-Hamnet, completely independent of the internet. The map above is the network built by HAMs in Austin, Texas. Basically it’s a bunch of hacked Linksys routers connecting wirelessly over a wide area. Plug a laptop into any of the routers and you can trade messages, files and live video back and forth.

This is possible because it just happens that the frequency range of off the shelf wireless routers overlaps with amateur radio frequencies making it legal for HAMs to boost the range of these devices. That and the fact that several models of ubiquitous Linksys routers are cheap and easy to hack.

All you do is take your Linksys router, screw in a better antenna (note the one above made with a tin can), load some open source software on to it, scatter them around town and you’ve got a wireless data network. Note that the routers in this configuration are communicating with each other. To hook your laptop into the network you have to connect it via an Ethernet cable to one of the nodes or set up a wi-fi network at a node. The routers can even be powered by small 12 volt batteries or solar panels. To be clear, this is a wireless network that is independent of the internet (though you could route the internet over it). Such a network could be used in an emergency such as an earthquake or weather event to send digital messages. It’s also the means by which I could continue to send out cute cat photos even if things go full-on Cormac McCarthy

You could use this same hack, not exactly legally, to solve networking problems in a large house, business or rural property. And the same method has been used to set up data networks in developing countries. In practice it’s doubtful that the Man would ever get around to busting someone without a HAM license from setting up a network or routing the internet over it. As long as you’ve got line of sight between your antennas it’s possible to send information over impressive distances–with the right antenna, some HAMs have managed to get the signal out as far as ten miles with a stock router and no boost in power. And the network is self healing. If one router goes out the other routers take on the traffic.

For more info on how to set up a network like this see www.broadband-hamnet.org. or watch this series of videos. There’s also a free e-Book: Wireless Networking in the Developing World.

Cat photo kidding aside, this relatively simply hack has potential to help a lot of people.

This post was inspired by a lecture given by Gary Wong, W6GSW at the Pasadena Radio Club.