Different foods and dishes require different cooking temperatures. The following guide is for an aluminum dutch oven. Increase the number of briquettes by about one-fourth for a cast-iron oven. Actual temperatures will vary due to charcoal quality and weather.
| Desired Temp Range | Ten-Inch Oven | Twelve-Inch Oven |
| 250-300 – Low | 8 on top/6 under | 10 on top/8 under |
| 300-350 – Medium | 10 on top/7 under | 10 on top/7 under |
| 350-400 – Hot | 12 on top/8 under | 14 on top/10 under |
| 400-450 – Very Hot | 14 on top/9 under | 16 on top /12 under |
When coals are ‘hot’, they are barely covered with white ash and you can hold your hand near them for only 2 or 3 seconds. You can hold your hand near ‘medium’ coals for about 5 seconds. Low coals are covered with ash. You should be able to hold your hand near them for about 7 seconds.
Some dutch oven cooks use the “three up, three down rule.” For 325 degrees in a 12-inch diameter iron oven you need 12 briquettes + 3 = 15 briquettes for the top and 12 briquettes – 3 = 9 briquettes for the bottom. To get 350° F, add one more coal on both the top and bottom. Each two additional coals will give you about 20° F more heat.
The objective is to get the oven hot enough to cook the food before it dries out, yet not so hot you can’t control the cooking process. In most cases, if the food is sputtering and popping a lot, the heat is too high. Using the tongs, remove about one fourth of the briquettes at a time from the top and underneath until the cooking slows to a steady simmer.