HEAT TRANSFER
Our mission - making a better barbecue pit - is an engineering
challenge. So why not jump in with some basic barbecue
thermodynamics?
Heat flows from hot to cold by three modes:
- Radiation - where a hot object emits infrared
energy that is absorbed by a cooler one (e.g., broiling).
Radiation requires a clear line-of-sight from the heat source to the
meat, and proximity is critical, as energy drops off rapidly with
distance.
- Convection - where a fluid or gas is
heated and carries the heat to the food (e.g., a deep fryer).
Your kitchen oven (whether it's a "convection oven" or not) moves heat
via convection - the gas or electric element (at the bottom) heats air,
which rises, cools as it gives its heat to the food, and sinks back
down to be reheated. The medium can also transport moisture,
flavors, etc. to and from your meat.
- Conduction - where direct contact occurs
between hot and cold objects (e.g., frying). Note: whether you're
broiling, baking, or frying, 99% of your meat's volume - all but the
outer surface - is being cooked by conduction from the outside
inwards. The heat transfer mode only determines how the heat gets
to the meat's surface.
As we'll learn in How Meat Cooks,
we're raising the meat's internal temperature way past "well-done" to
break down the tough connective tissues into silky, flavorful
gelatin. This denaturing takes time, and we have to do it without
overheating any part of the meat. That requires low temperatures
and no hot spots - impossible when frying and difficult when broiling
without rotisseries, etc. So we use convection - we bake the meat
- which also imparts aromatic flavors from the fire. A barbecue
pit is just a wood-fired oven.
Copyright 2008 | Karubecue LLC | Southlake TX
| Patent Pending
|