Grilling vs BARBECUE

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Grilling is NOT barbecue

The terms “grilling” and “barbecue” are used interchangeably by most people but they are most definitely not the same. Technically (and loosely speaking), grilling is cooking food using radiant heat (which is also what happens when you broil a steak in your oven). Radiant heat transfers energy in wave form and isn’t “hot” until it hits an object. 

A Quick Primer on Types of Heat

Radiant heat
Literal heat waves. The sun emits radiant heat. It’s not hot in space because space is a vacuum; the sun doesn’t “hit” anything. Once the heat waves from the sun enter the Earth’s atmosphere they warms air particles. (Ambient temperature is cooler at higher elevations because the air is thinner; fewer particles to be warmed by the sun’s radiant heat.)
 
Convective heat
Heat moved through motion. Think of the ocean’s gulf stream. Or forced air heating. The warm particles of water or air move from one place to another.
 
Conductive heat

Heat transferred through contact.  A pan on a stovetop being heated by a gas flame.

Most cooking processes involve a combination of heating methods. As an example, let’s boil some potatoes in a pot filled with water.

The pot is warmed by the conductive heat of a direct flame; the pot transfers (conducts) heat to the water; the hot water rises and circulates (convection); as this hot water comes into contact with the potatoes it warms them by transferring heat via conduction.

Let's compare that to cooking in my offset smoker

I’ll start a fire by lighting newspaper, which heats charcoal in my chimney starter (all conduction so far). As the charcoal burns it transfers heat to the other coals via all three heat methods. Once all the coals are burning super hot I dump them into the fire box. I build a crosshatch of logs on top of the coals. 

The logs directly touching the coals catch fire via conduction and radiant heat. Eventually all the wood burns; as it’s burning the hot air rises and travels through the (separate) cook chamber. Convection at work. The hot air (and smoke) flow through the cook chamber above, below, and around the food resting on the grates. The hot air transfers heat (via conduction) to the cooler food and to the grates and to the metal shell of the smoker itself. The surface of the food gets warm and begins to transfer heat to its cooler interior (conduction).
 
Grilling is radiant heat, some conduction, and a smattering of convection. Smoking food involves mostly convection and conduction. Other barbecue methods involve direct heat, which means radiant heat is involved.

We’ll get to barbecue in a moment. First, a mini rant.

I’ve never understood the reasoning behind grill pans. A grill pan uses conductive heat; grilled food is cooked over radiant heat.  The different heating methods create different-tasting food.

One reason for this is when you burn wood down to coals you can achieve temperatures much higher than most ovens can reach. The surface of a hot coal can be 2000 degrees Fahrenheit, though that heat dissipates quickly as it gets further from the coal. A grill grate set two inches from the charcoal might be 600 degrees. 

Broiling is more akin to grilling than cooking in a grill pan.

So…what exactly is barbecue?

We’ll talk about that next time 🙂 

Cheers,
L.R.

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