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). A small triangle of bottom flap will usually come loose in the process. Glue this 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
Close-up detail of rack and binder clip.
This is an ideal cooker for youth projects, as it is easy to make and 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 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. 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 ).
EZ-3 assembled and folded flat for storage and transport.
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 four to five inches deep. Cut out this triangle+rectangle shape (it will look a bit like a child's outline of a house) and foil it and score a fold along what would be the front edge of the cooker (between the triangle part and the rectangle part). 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 (Sharon will try to get a good photo of a booster in operation the next chance she gets).
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.
Sharon has recently found a source for a larger sized cooking bag and as soon as she figures out how to afford a box of 100, she will be 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.