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Regardless of what you have heard or read from pseudo pit masters, there is no "direct heat," there is no "indirect heat". There is only heat.
According the to irresistible laws of physics, heat moves from regions or objects of higher temperature to regions or objects of lower temperature until a state of equilibrium is reached. Heat moves in only three ways, by conduction, convection or radiation.
Conduction is the transfer of heat by intimate contact - who said physics couldn't be fun - and moves from molecule to molecule. For example, the grate or grill upon which the meat rests, having a higher specific heat than the meat, conducts heat to the meat. That is why, when the grill is right, that the beautiful brown stripes magically appear upon the surface of a steak. Then the exterior of the meat conducts heat to the interior, molecule by molecule. Conduction is extremely important in barbecuing because we must conduct the heat from the exterior to the center so slowly and gently that we do not dry out the exterior. Using low temperature over the long period is the essential distinction of barbecue from roasting or broiling. Not just incidentally, it also allows for more flavoring and more fun time. Let's hear it for conduction!
Convection is the transfer of heat by movement of heated masses, i.e. air, water, oil. In an oven, an enclosed grill or in the path of heated air, convection is at work. Convection allows us to remove the meat from directly over the coals and, therefore, tend the coals without disturbing the meat. It does not restrict the amount of meat which can be simultaneously cooked to the surface area of the coal bed and fat dripping from the meat does not drop into the coals.
Radiation is the transmission of heat in waves of energy resulting from vibration of excited molecules. As when your tongue trembles at the taste of succulent, savory barbecue, it radiates ecstasy to your brain and other pleasure receptors. In a closed grill, meat receives radiated heat from the coals, if it is over them, and from the heated mass of metal in which it is enclosed.
This may be more than you really want to know about it, but "the intensity of the radiated heat is directly proportioned to the temperature of the source and inversely proportioned to the square of the distance." In practical terms, this means that meat on a grill over coals and below a metal cover may receive equal radiated heat from both. Those who have cooked on a grill with tiered racks have no doubt observed that those pieces of meat on the top rack (nearest the metal) may brown more quickly than those on the lowest tier directly over the coals. Likewise, if you put bread on the top shelf of an oven, the top browns faster than the bottom, and conversely.
Microwaves are not, strictly speaking, heat. They generate heat within meat by the agitation of its molecules of water. This is the only cooking (?) process in which meat does not depend entirely upon conduction from its exterior to raise the temperature in the center.
As a practical matter, in an enclosed grill, unless meat is suspended from or resting upon a non conducting surface, it is at all times receiving heat by all three transfer methods.
What does all this mean to the barbecuer or the griller? Meat does not care how it receives the heat. What is essential in barbecuing is that the exterior of the meat does not over cook, dry out, burn, blacken or char before the interior reaches an acceptable temperature. This requires that meat receive a constant flow of heat, in any form or forms, at a temperature low enough to permit conduction, within the meat, time to work.
In this respect, water is the great ally. Water absorbs and conducts heat much better than dry tissue. Therefore, the more moisture that we can retain within the meat, the faster it will conduct and the more tender it will be when it is finished. Everybody knows that, at sea level, water boils at 212 degrees Fahrenheit. It, therefore, follows that, if we keep the temperature of the exterior of the meat at slightly below the boiling point of water, conduction is improved and tenderness is retained.
For a barbecuer, the effective grill is one which will allow its operator to present heat by all three forms in a controlled fashion over long periods of time and have ready access to the meat and to the coals. The greater the mass of the cooker and the coal bed, the more consistent the transfer of heat and the more time for enjoying all the ancillary activities for which barbecue has become famous.
In the final analysis. There is no direct heat. There is no indirect heat. There is only heat. The judicious use of heat in any form and the creative use of the time during which it is applied is what barbecue is all about.
Pit roasting, v.
To cook meat and/or vegetables in a hole in the ground. A large fire is burned down in a pit and, using various methods, part or all of the coals are removed, the meat is wrapped, placed in the pit and covered with various materials including some of the coals and allowed to cook much like a pot roast.
A piece of meat suitable in size and provenance to be roasted.
To cook large pieces of large animals or whole smaller animals in dry heat at temperatures ranging from 300-450*F. Normally meat chosen to be cooked in this fashion are the more tender parts or specimens. Meat may be basted to prevent drying. Meat from naturally fed animals may require larding, introduction of fat through the meat with special needles, and barding, covering with layers of fat, to render it tender.
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Smoky's 5th basic position for really great barbecue'n.
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