Tuesday, June 20, 2006

Thinking Inside of the Box

Cardboard Box Oven


A cardboard box will make an oven -- and it works just as well as your oven at home! There are different ways to make a cardboard box oven. The two described here are the most common, but you can dream up your own design. Good boxes for ovens include:

  • Brewery long neck beer returnable box (the best – heavy duty with a lid)
  • Whiskey or wine case boxes
  • Copy paper boxes

The principle is simple: Line a cardboard box inside and outside completely with heavy duty aluminum foil. Provide some means of keeping the food away from the coals. Use charcoal briquettes to control the temperature. A properly made cardboard box oven will last for many uses, costs practically nothing, and recycles a cardboard box. Not only that, it will bake things outdoors you thought could only be made indoors!

Style #1: The Open Top Box Oven

Cut off the flaps so that the box has four straight sides and bottom. The bottom of the box will be the top of the oven. Cover the box inside completely with foil, placing the shiny side out (hint: use Elmer’s glue to stick the foil to the box)

To use the oven, place the pan with food to be baked on a footed grill over the lit charcoal briquets. The grill should be raised about ten inches above the charcoal. In the picture below, soft drink cans raise the baking pan above the coals. Set the cardboard oven over the food and charcoal. Prop up one end of the oven with a pebble to provide the air charcoal needs to burn - or cut air vents along the lower edge of the oven.


Figure 1 - Simple open-top oven

Style #2: The Copy Paper Box Oven

The cardboard boxes that hold reams of paper, 10 reams of 8 1/2 by 11 inch paper, or 10 reams of 8 1/2 by 14 inch paper, will make very nice box ovens. Line the inside of the box and lid with aluminum foil. Use a sponge to dab some Elmer's glue around the inside and cover to hold the foil in place. Make a couple holes in the cover to let the combustion gases out, and make a few holes around the sides near the bottom, to let oxygen in.

Make a tray to hold the charcoal using one or two metal pie plates. You can either make feet for a single pie plate using nuts and bolts, or bolt two pie plates together bottom to bottom. Cut a couple coat hangers to make a rack to hold up the cooking pan. Poke the straight pieces of coat hanger through once side, and into the other.


Figure 2 - Box showing coat hanger wire rack

Put several lit briquettes on the pie pan, put your cooking pan on the rack, and place the cover on top. The first time you use this box oven, check it a few times to make sure that enough oxygen is getting in, and enough gases are escaping, to keep the charcoal burning. A nice enhancement would be adjustable vents on the bottom and lid to control the burn. Brass brads and disposable aluminum pie plate are some possible draft door materials.

Box Oven Tips

  • Control the baking temperature of the oven by the number of charcoal briquettes used. Each briquette supplies 40 degrees of heat (a 360 degree temperature will take 9 briquettes).
  • Experiment! Build an oven to fit your pans - or your menu: Bake bread, brownies, roast chicken, pizza or a coffee cake.
  • Construct a removable oven top or oven door. Punch holes on opposite sides of the oven and run coat hanger wire through to make a grill to hold baking pans.
    Try the oven over the coals of a campfire.
Field Trials

The C3 Psychoto-electro Arkestra encampment at the Peace Conspiracy Festival in June 2006 featured demonstrations of this apparatus. The copy paper box model was built and used. A slight field modification had to be made to allow enough air for comubstion. A slit door 1" by 2" was cut in the side of the box a couple of inches from the bottom. This allowed the oven to burn perfectly with the lid snugly on.

Few festival-goers had heard of such a thing (although they are all veteran hippie campers!) and quite a bit of interest was generated. Of course, having some good things to eat did not hurt at all. Here's what was prepared:
  • White bread - the box accommodated three standard loaf pans side by side, making for an efficient use of 9 briquettes to bake 3 loaves. Grocery store frozen dough was used.
  • Biscuits - regular canned biscuits cooked up wonderfully, crispy and brown on the outside, yummy soft on the inside.
  • Dump Cake - by substituting lemon/lime soda for water or milk in a cheap box cake mix, then adding goodies like nuts, dried fruit or cherry pie filling, delicious cakes!