What the Nose Knows - Avery Gilbert [47]
Some spices are used by many different cultures. What makes a flavor principle distinctive is its specific combination of seasonings. Consider lemon, a widely used flavor source. Add cinnamon, oregano, and tomato and you’ve got a Greek principle. Add fish sauce and chili and you’ve got Vietnamese. The extensive overlap in ingredients across flavor principles means that every traditional cuisine on the planet can be prepared from a very short shopping list. The thirty or so principles Rozin describes in her book require about four dozen ingredients. All the flavors of world food culture can fit into a single grocery bag.
Liz Rozin’s theory of food aroma strikes some people as too minimalist to account for the richness of human cuisine. What they fail to appreciate is the power of combinatorics, which makes it possible to generate huge numbers of flavor variations from a few basic odorous elements. The Chicago chef and restaurateur Charlie Trotter understands this. “You can prepare forty dishes from six ingredients,” says Trotter. He likens creative cooking to jazz improvisation. A chef who has mastered the basic repertoire—the classical flavor combinations—can improvise endless new dishes with only a handful of spices. Thus the cook and the chemist have arrived at the same fundamental truth: sensory diversity is achieved with relatively few ingredients. The chemist can re-create the aroma of any foodstuff with fewer than a thousand odor molecules, and the chef can build any global cuisine with a few dozen spices. The amazing variety of human cuisine, at the chemical as well as the aesthetic level, is a matter of basic themes and endless variations.
THE CORNELL UNIVERSITY evolutionary biologist Paul Sherman is another scientist rethinking the assumption that all variation in food habits is cultural. Sherman studies how spice use relates to human survival. He and his collaborator Jennifer Billing were intrigued by the fact that spices often have antimicrobial properties: they contain natural chemicals that kill bacteria and fungi. Could the point of cooking with spices be to reduce spoilage and food-related illness? To test their idea, Sherman and Billing assembled a collection of ninety-three cookbooks from thirty-six countries. From these, they selected 4,578 meat-based recipes and meticulously noted what spices were used in each.
On a worldwide basis, nearly every meat dish (93 percent) had one or more spices. The results varied, however, with a country’s climate: the number of spices per recipe increased with the average annual temperature. In Finland and Norway, for example, one-third of recipes used no spices at all. In contrast, in Ethiopia, Kenya, Greece, India, and Thailand, every recipe called for at least one spice. Sherman and Billing ran other statistical analyses and found that average annual temperature was correlated with the proportion of recipes containing spices, and the total number of spices used. Since unrefrigerated meat goes bad faster in a warm climate, more spices might mean better protection against spoilage. Sherman and Billing examined the antibacterial power of the various spices, and found that the hotter a country, the more bacteria species are inhibited by the local selection of seasonings. They conclude that while spice use is something we do because it tastes good, it also rids food of pathogens and therefore provides