I'm a vegetarian. I have been for the past 20 years and while I don't miss meat, there is something about a steak, a hamburger, a fillet of salmon cooked on a barbecue that is strangely appealing.
Cooking a meal - even a veggie dog - over an open flame just seems to make for a more satisfying meal. Even a campfire adds a certain flare, although over the years, I have found that campfires also add a fair amount of ash and soot.
Outdoor cooking, over a flame, just seems to make food taste better. Knowing a little science can step it up a notch further.
The flavour we associate with meat results from cooking. Raw meat is chewy, somewhat bland, with a fleshy, metallic taste. It is not very appealing and certainly doesn't match a well -cooked steak.
The application of heat results in chemical reactions between sugars, proteins, fats, and other molecules. It can even result in chemical transformations producing new molecules such as the polyaromatic hydrocarbons that result from burning. Burnt food is not good for you.
The combination of molecules is distinctive for different types of meats and even for different cuts. The subtle flavour differences between a filet mignon and ground beef are a consequence of the molecular re-combinations that occur while cooking.
In the parlance of food-tasting professionals, the flavour of cooked meat is a composite of at least two distinct components. The first is the meaty, brothy "base notes". They are similar in all forms of meat and are the flavours that tell us that the stuff we are eating is meat, not broccoli or turnip.
These "base note" flavours arise from the amino acids in the proteins of the meat reacting with the sugars in the muscle tissues. Since all animal proteins are made up of roughly the same amino acids and sugars, it is not surprising that the underlying flavour of all meats is roughly the same.
The second component of the flavour of cooked meat are the lighter "species notes". These are compounds that are specific to the type of flesh that is being cooked. They are the ones that identify a flavour as beef and not chicken or lamb. Indeed, it is an absence of species notes that leads to the "everything tasting like chicken" syndrome.
These lighter flavours are primarily due to compounds formed in the fats of the animal as it is heated and they are vapourized during cooking, resulting in the aroma that we smell while tasting barbecue. Our sense of smell is as much involved in the overall experience of a meal as our sense of taste. And species notes can be quite specific, reflecting not only the type of meat but also such things as an animal's diet since many metabolites are stored in fat.
As to the actual chemical compounds that produce flavour in meat, it is very complex and not completely understood. There are more than 30 different starting compounds involved and several hundred molecules which result from cooking. Flavour is also dependent upon cooking time, cooking temperature, the acidity of the meat, the structure and acidity of any marinade that is used, the degree of moisture when cooking, and many other factors.
Still, even with all of this complicated chemistry, the basic principles of cooking over a barbecue haven't changed much since pre-historic campfires. Generally speaking, the more heat applied the more flavour that develops but the drier the meat gets.
All of the chemical transformations that take place require energy and the amount of energy is controlled by the temperature and the duration of the cooking process. As a consequence, slow cooking over a low heat can sometimes be more effective than fast cooking over a high heat - especially where flavour is important.
But for some types of meat slow cooking can result in toughness. In broad terms, animal tissues contain two general types of proteins - muscle and connective tissue. The long fibres in muscle tissue contract with heat and dehydrate so that they toughen up with time. Connective proteins, on the other hand, turn to gelatin.
Cooking any meat over a barbecue is a competition between these two types of material. Muscle protein starts off soft and gets hard with heat and time whereas connective tissue starts chewy and tough but softens up as it cooks.
Good barbecuing must take into account a proper balance of tenderness and toughness. Time and temperature must be adjusted for the cut of meat. For example, with a well-marbled cut, a longer cooking time at a lower temperature produces better results. On the other hand, with a nice lean piece of meat, a quick flash on the barbecue might be just the thing to get a rare steak.
And for some people, that is a perfect summer menu.
