What the Nose Knows - Avery Gilbert [46]
Adding meat greatly enhances the diet. Chimpanzees in the wild are big fans of monkey meat, but even with their powerful jaws they take hours to gnaw the raw flesh from a bone. Given the effort involved, raw meat isn’t a routine source of nutrition for chimps. Nor would it have been for early hominids. A Homo erectus female (our evolutionary cousin) would have needed six hours a day to get all her calories from raw meat, according to Wrangham’s calculations. Cooked meat, however, is a different story: it is nutrient-dense, easily chewed, and rapidly consumed. The time saved by cooking changes our behavior patterns. Where all other large primates snack throughout the day on raw fruits and leaves, we eat a few discrete meals, leaving more time for other activities. The widespread popularity of cooking among protohumans meant that powerful jaw muscles and large teeth were no longer essential, and as their evolutionary advantage shrank, so did they. In the last 100,000 years our teeth and jaw muscles have become even smaller, making possible finely controlled chewing movements of the tongue and jaw. The more nimble modern mouth makes an easy-to-swallow “bolus” of food and releases more aroma in the process. In the long run, cooking has literally changed the shape of our face.
COOKING HAS ALSO changed our sensory world: it introduced novel aroma molecules and whole new classes of smells. The savory notes of roasted meat, toasted nuts, and carmelized vegetables were rare accidents before we fired up the Pleistocene barbecue. More new smells—baked bread and boiled mush—arose with the cultivation of wheat and other grains about 12,500 years ago. Sheep, goats, pigs, and cattle were all domesticated roughly 10,000 years ago. With them came the smell of butter and the fermented bouquets of yogurt and cheese. As early villagers mastered the art of fermentation, the heady aromas of beer and wine joined the mix.
We are a cooking species, and the smell of an impending meal is woven into our biology. Food aroma is an invitation and a spur to action. Even before the first bite, it triggers an elaborate sequence of physiological events: salivation, insulin release by the pancreas, and the secretion of various digestive juices. The aroma of bacon, at a level so faint it can’t be consciously identified, has been shown to trigger the flow of saliva. This would not have surprised cookbook author James Beard, who once said, “Nothing is quite as intoxicating as the smell of bacon frying in the morning, save perhaps the smell of coffee brewing.” We expect to be stimulated en route to a meal—the anticipatory smells of cooking have become almost a biological requirement. This is a big headache for manufacturers of prepared foods. The physics of microwave heating doesn’t create the toasted, roasted, and caramelized notes that signal impending “doneness.” Food companies spend a lot of time and money on technological work-arounds to restore these missing scents.
IN ADDITION TO cooking food, we spice it. Spice use is a universal human habit, though there are significant regional differences in the spices that are used and how they are combined. What qualifies as a spice? In one definition, it’s “any dried, fragrant, aromatic, or pungent vegetable or plant substance, in the whole, broken, or ground form, that contributes to flavor, whose primary function in food is seasoning rather than nutrition, and that may contribute relish or piquancy to foods or beverages.” Roots, seeds, dried leaves, even aromatic lichens fit this definition; including fresh herbs adds still more materials. There are a lot of spices, and yet, like the huge number of possible smells in the world, the closer one looks, the more this apparent diversity can be simplified. At the core of each of the world’s great culinary traditions is a small group of spices and flavorings. A perfumer would think of these combinations as an accord, the key ingredients that define a style of perfume. The late food expert Elisabeth Rozin called these combinations “flavor principles”: “Every