Grilling and Broiling: Radiation
Grilling and Broiling are the modern version of the oldest form of cooking - to cook by direct heat transfer from radiant heat of a fire or the barbecue. In the UK, grilling is the same as the US broiling, i.e. heating from above, while in the US grilling relates to heating from below. It's all just to confuse each other by using the same word for subtly different meanings. In grilling, most of the heat transfer is infrared radiant energy; the sources of the heat glow red and are intense radiators of infrared electromagnetic radiation. These have intense heat: glowing coals and the bars on an electric grill are at about 1100oC (2000oF) and gas flame is 1600oC (3000oF), whereas for comparison the walls of oven for baking are a mere 150 - 220oC (300 - 430oF).
The vast amount of energy from a grill - a coal or metal grill radiates 40 times the energy of an oven - is the great advantage, but also drawback of grilling and broiling. It enables quick browning of the food surface and so delicious and rich flavours are created, but the much slower conduction of heat to the centre of the food can result in food browned on the outside but raw in the centre. Hence, the trick is to have your food far enough from the grill to brown more slowly and match the slower rate of conduction into the centre of the food, so there is a richly flavoured dish throughout the ingredient. Alternatively, you can start with a quick browning close to the grill, then finishing the cooking at a greater distance further from the heat source or in the oven to result in cooked food with a beautifully grilled surface.
- Stobart, T. (1981) The Cook's Encyclopedia: ingredients & processes, Harper & Row. ISBN 0060141271.