EZ-3 taking advantage of the August sunlight.
Designed by Sharon Cousins (standing on the shoulders of giants), the EZ-3 might best be classified as a small hybrid panel-oven, since the whole cooker goes into the cooking bag (eliminating the need to bag the cooking vessel). A cut out, foiled box corner is sized so that the whole cooker can be eased into a Reynolds turkey sized oven bag. Distance from the corner along the bottom edge can be 12" - 13", and the vertical measure can be 17" - 18" (which can include the box flaps, taped upright with duct tape or other heavy-duty tape). This is a surprisingly efficient little cooker for up to one quart of food and works very well with either small, dark pots or pint or quart cooking jars. It is Sharon's favorite cooker for heating up her solitary summer lunches.
To make an EZ-3, measure, mark, and cut out the box corner (first taping up the top flaps if you need them to attain the proper height). One or two small triangles of bottom flap will usually come loose in the process. Glue these triangle back in place with white or wood glue. Do not glue the whole bottom together if you want to be able to fold the cooker flat for storage and transport! When that glue is dry, foil the inside of the cooker
The whole cooker is enclosed in a Reynolds turkey size oven bag. When setting up the EZ-3, use a binder clip to secure the cooker. A 6" cake cooling rack or three or four small pebbles elevates the food so light can get under it, improving the efficiency. The cooker is gently eased into the oven bag. The opening of the oven bag is rolled up at the back of the cooker and secured with two clothespins. When folding for storage (after making sure any vapors have dried from the cooker and bag), remove the binder clip and fold flat, with the folded oven bag inside the cooker, and secure with the binder clip.
The whole cooker is enclosed in a Reynolds turkey size oven bag. The opening of the bag is rolled up at the back of the cooker and secured with a couple of clothespins
This is an ideal cooker for youth projects, as it is easy to make, is easy to aim using the shadow, and it works well. The recipe SharonID's Solar Project Soup in the Soup section of Recipes was developed for EZ-3 youth projects. It lets each person/youth make an individual pot of vegetable soup, with the vegetables set out so that each person fills their measure with ones they like.
The EZ-3 is also a good cooker for couples or people who live alone and only cook small quantities of food (for more than one food, make additional cookers) or for people who want a small cooker for backpacking or traveling. Homeless people in some circumstances might find it useful (you can even heat prepared food in the can if you open the can slightly to vent and slide it into a thin, black sock), and families with one member with special dietary needs might find it useful for small amounts of special foods. It's a great cooker for cooking up to a quart of anything, from soup stock to rice to fruit sauces (see Fruit ). It is also ideal for making a quart of solar coffee (see Beverages ). With the addition of a small, dark lidded pot (3-4 cups or .75-1 liter) the EZ-3 does a very good job of baking cake, cornbread, yeast bread, a big fat cookie, brownies, scones, a giant muffin, and more. Weight watchers might find it useful to be able to make a small amount of a special treat to avoid the temptation to overeat.
To increase the efficiency of an EZ-3, a small front booster panel can be made by tracing the bottom of the cooker on a flat piece of cardboard and marking a rectangle the width of the cooker and six inches deep. Cut out this triangle+rectangle shape (it will look a bit like a child's outline of a house) and score a fold along what would be the front edge of the cooker (between the triangle part and the rectangle part) and foil it.
EZ-3 booster — cut, scored, and foiled
In use, place the cooker on the triangle part of the booster and use a small pebble or two underneath to elevate the booster reflector to a good angle for shining into the cooker and onto the pot or jar.
EZ-3 assembled and folded flat for storage and transport.
For better winter cooking efficiency, make two EZ-3s in slightly different sizes, so you can nest two for the added insulation and bag the nested pair. In combination with a front booster panel, this double EZ-3 arrangement reached temperatures of 225F on a clear day in January, at 47 degrees north latitude, with ambient outdoor temperatures in the upper twenty degree (F) range.
Close-up detail of rack and binder clip.
Sharon has recently found a source for a larger sized cooking bag and is developing an slightly larger EZ-3 in hopes of coming up with one that can do a good job with a half-gallon cooking jar. She also reports that the oven bags used to enclose an EZ-3 last much longer than bags used to enclose cooking vessels.
Sharon is primarily cooking at 47 degrees north latitude with an occasional foray into the San Jose CA area. She suspects that further south the EZ-3 will work better if it is tipped back a bit, with a stick or small board or pebbles under the front of the cooker to lift it. Level out the bottom with a false bottom (foiled, of course) and figure out some way to shim the corner so your pot or jar will still be reasonably level. Also, opt for slightly shorter and slightly wider at the bottom, within the limitations of your bag. Further south, you need less height and more side-wall.
EZ-3 also handles wind fairly well, if you give it a little support so it doesn't just blow away. You can put a couple of foiled chunks of rocks in it to add a little weight, and it can be braced behind with anything heavy—water jugs, big rocks, wood chunks, bricks, etc. Close it as tightly as you can if it will be cooking in the wind, to keep billowing to an absolute minimum
EZ-3 up and running, with booster in place.
Youth from an Idaho based Roots and Shoots club celebrate the end of a successful EZ-3 solar cooker project
External Links
- EZ-3 Solar Cooker Home Page (under construction)