Lots of dutch oven cookbooks tell you how many charcoal briquettes to put under and on top of the oven. This is the easiest way to cook since every coal is similar and consistent. If you are like me and use real wood for your outdoor camp cooking coals, it doesn't help much. Also, different brands of charcoal give off different amounts of heat. But, let's say you are going to use charcoal...
The normal formula is to use twice the number of briquettes as the diameter of the oven. For a 12 inch oven, you would use 24 briquettes. Depending on the type of cooking you are doing, you need to make the heat come more from the top or bottom of the oven. For example, too much heat on the bottom will burn bread.
To do this, you place more or less of the briquettes on the lid.
Here is a simple chart:
|Baking||More heat from top so bottom does not burn.|
Place 3/4 coals on top and 1/4 underneath.
|Roasting||Heat comes equally from top and bottom.|
Place 1/2 coals on top and 1/2 underneath.
|Stewing, Simmering||Most heat from bottom.|
Place 1/4 coals on top and 3/4 underneath.
|Frying, Boiling||All head from bottom.|
Place all coals underneath.