How Hot Is It?
Barbecuing with the right level (or levels) of heat is just as important as the way you arrange the coals. Charcoal barbecuing does not require anything like the precision of baking or candy-making but, then again, trying to barbecue everything over the same level of heat oversimplifies charcoal cooking and misses big opportunities for superior tastes and textures.
There are really two ways of knowing how hot a charcoal fire is. One is to use the thermometer in the lid of your barbecue, that is, if your unit has one. If you cook often with indirect heat (barbecued chicken, pork ribs, prime rib), look for a unit with that feature. Otherwise you will be tempted to lift the lid too often, just to see how the briquettes are doing, and that causes troublesome peaks and valleys in your cooking temperatures.
Note: For the best chance of a successful cook each and every time, always ensure you start your cook with the recommended fuel quantities suggested for each setup and temperature range.
The Hand Test
The other way to know the heat is to extend your palm over the charcoal at a safe distance. Imagine a soft drink can is standing on the cooking grill, right over the lit fuel. If your palm was resting on the top of the can, it would be 15cm from the cooking grill. That’s where you should measure the heat of charcoal. Always pull your hand away from the heat before it hurts, and be sure that nothing flammable, such as a sleeve, is dangling from your arm. If you need to pull your hand away after 2 to 4 seconds, the heat is high. If you need to pull your hand away after 5 to 7 seconds, the heat is medium. If you need to pull your hand away after 8 to 10 seconds, the heat is low.
High (230-2900C): 2-4 seconds
Medium (180-2300C): 5-7 seconds
Low (130-1800C): 8-10 seconds
High (250° to 300°C): 2 to 4 seconds
Medium (200° to 250°C): 5 to 7 seconds
Low (170° to 200°C): 8 to 10 seconds