For many years an Australian professor, John Prescott, an expert in the field of sensory science, has pursued an interest in the perceptions that shape our food preferences. In his book Taste Matters: Why We Like the Food We Do, he has tried to describe the factors that determine which foods we like and which we reject. In a slightly cryptic turn of phrase, he sums this up as “we eat what we like and we like what we eat.” To a large extent this is driven by mouthfeel.
Prescott’s way of describing our food preferences glosses over how complicated it is to explain why we eat as we do. Fundamentally, we are driven by desire and drawn by enjoyment. Eating is a hedonistic activity. We eat what each of us thinks tastes good. In this regard, we are motivated by the same mechanism as the one that governs sexual behavior. Both food and sex improve our ability as a species to survive in the long run as evolution takes it course. Food supplies the necessary nutrition and sex the possibility of reproduction.
The enjoyment value of food is based on a person’s individual preferences rather than on its nutritional content. What we enjoy at different stages of our life can depend on genetics and a whole series of other factors, such as the eating habits of our mother during pregnancy, circumstances while we were growing up, how we were raised, our education and cognitive makeup, as well as our culture, tradition, and ethnicity.
Some food preferences are inborn and universal. We like food that tastes sweet or imparts umami and reject food that is too bitter or sour. We also prefer food that is somewhat salty. In the course of evolution, these built-in food choices have improved our chances of survival by steering us toward food that is rich in calories and away from that which is poisonous. In many parts of the world food is readily available and relatively inexpensive. On the downside, our propensity to seek out food that is fattening, in combination with this easy access and low cost, is one of the reasons for the growing obesity epidemic in both rich and even poor countries.
Nevertheless, our preference for these basic tastes does not necessarily mean that we all like the same kinds of food; in fact, far from it. There are many other nuances of taste apart from the basic ones that play a role in our choices, an important one of these being mouthfeel.
Even though it is quite easy to identify some characteristics that are shared by the food we like, it is much more difficult to pinpoint them in the food that we dislike. We reject foods for a whole variety of reasons and the only common factor is whether it is too bitter or extremely sweet or salty. As we grow older we sometimes develop preferences for a certain degree of bitterness in our foods—for example, coffee, tea, hoppy beer, spinach, and tonic water—even though we do not have an overall preference for bitter foods.
The development of hedonistic reactions to the many-faceted sensory experiences related to food actually mirrors the complex interplay among the multitude of factors that govern human behavior and social interactions. One of the best-known examples is the association between tastes and personal experiences of either a positive or a negative character. Another example is the way in which we can become accustomed to something after having tasted it a number of times and possibly even end up seeking out food with that particular taste. A third example is the development of taste preferences in social settings that involve us in the preparation of food and meals. These last two examples can play an important part in what we might call food or taste adventurousness, and in that way counteract neophobia—that is, the fear of anything new or novel—in this case, something that we have never eaten before.
Until the age of about two, small children eat what their parents eat, provided that they are allowed to do so. They are total omnivores and the underlying biological principle is that children quite unconsciously trust that the food that their parents are eating is also safe for them. In addition, the food preferences of newborn babies are to an overwhelming extent governed by the food that their mother ate during pregnancy.
From the age of about two to three years, children slowly begin to develop a degree of independence, which again has a biological consequence in that they are less inclined to try food that they do not already know. This is a sort of neophobia, which is a relevant way of approaching the dilemma of the omnivore—to be willing to eat everything, but not to run the risk of eating something that is poisonous. The extent of this food neophobia is only partly a matter of genetics.
Children participating in a school-garden project tasting a soup made with vegetables that they themselves have grown. Here there is no food fussiness!
Food neophobia is not a question of simply liking or not liking foods that one has never tried before. Rather, it is the fear that one might possibly not like something new if one tastes it because it could turn out to have a bad taste. This lack of adventurousness with regard to food leads to a similar lack of adventurousness when it comes to tasting it. And this means that it is quite possible that someone has not even tried to find out whether something new might actually taste good or bad. It is not unusual to hear children claim to dislike certain foods, even though they have never tasted them.
Food neophobia is often associated with being a fussy eater. But food fussiness is not an absolute condition; it depends on social context. Much to their frustration, parents experience this when they see their children who are fussy at home gladly eat all sorts of food at other people’s houses. School projects that involve children in growing their own vegetables and preparing them for themselves and their classmates often illustrate this point quite clearly. The teachers say that the children never reject food when they have taken ownership of it and how it tastes. Being fussy is not in and of itself an undesirable trait; rather, it is a very natural condition that can be influenced and changed, although seldom by the use of promises, threats, or finger-wagging.
Children often refuse to eat or try certain foods as a way of asserting their power in relation to the adults. This method is extremely effective and most families with children have probably experienced, more than once, that hour just around dinnertime when fussiness increases and even the children’s favorite dishes will not make them happy.
Normally children outgrow food neophobia by the time they are teenagers, but it stays with some people into their adult years. Research has shown that one way to defeat this fear is to be exposed to new foods and new tastes over and over. After having tasted something between four and eight times, one learns to appreciate it much more. What happens as a result of this repeated exposure to something previously untried is, in all likelihood, that the fear of the new is reduced and might then eventually disappear altogether.
Another way to break down the barriers that prevent us from trying something new is to introduce it gradually together with a food that is already familiar, a so-called gateway food. A third option is the active acquisition of knowledge in a different setting and in the company of others where one feels stimulated to display curiosity, participate, and take ownership of one’s own tastes.
Texture is an important measure of quality for both raw ingredients and prepared foods. On the one hand, a poor or undesirable texture does not serve to nearly the same extent as taste and smell indicate whether a particular food is fit to eat. A soufflé that has collapsed is just as edible as one that is still puffed up, but there is a huge difference in the mouthfeel of the two. On the other hand, it is a very legitimate indicator of quality with regard to the freshness of raw ingredients, such as vegetables and fruits, as well as a way to judge the ability of a cook to prepare and serve outstanding dishes.
Even though there might be cultural, psychological, social, and age-related differences, the texture of the food must not evoke memories of inedible things. For instance, most people would reject food that has the mouthfeel and taste of cardboard. Here again, though, there is the matter of growing accustomed to certain foods and learning to eat those with textures that one initially found foreign and strange, even unappetizing.
When one wants to acquire knowledge of another food culture, it often amounts to accepting unfamiliar textures or combinations of textural elements in novel contexts. Many who are used to Western-style food might find a silky tofu made from soy milk unappetizing and jellylike, but enjoy a sweet pudding or cheese made from milk with exactly the same texture, judging it to be soft and delicious. Another example is the case of vegetables, which in earlier times were expected to be cooked until mushy and practically unrecognizable. Now they are much more highly valued when cooked minimally to preserve their natural crispness and springiness.
Considerable age-related physiological differences may need to be taken into account when it comes to food texture. Babies without teeth and small children need to have pureed or finely chopped-up food that can be manipulated in the mouth without posing any danger of choking when it is swallowed. Elderly people may have difficulty chewing because of they have lost strength in their jaw muscles or have dental problems. In addition, the secretion of saliva may have decreased, leaving them with a dry mouth, which makes it harder to chew and swallow food that is hard or dry. A similar problem can arise for patients who have undergone chemotherapy or radiation treatments.
Research has demonstrated and lent weight to the empirical observation that we prefer different textures in different contexts, such as in the daily rotation of meals. Other experiments have shown that we are in love with textures that can be characterized as crisp, crunchy, tender, juicy, and firm, whereas such textures as tough, pasty, lumpy, slimy, and crumbly are often regarded as undesirable. In addition, there are certain combinations of textures to which we are naturally drawn, especially such contrasts as creamy/crisp, as in yogurt with muesli, and soft/firm, as in steamed fish with toasted almonds.
No one is surprised to learn that a meal is more than the food and a fabulous dining experience is not the result of only the energetic efforts of skilled Michelin-level chefs. More is required, not least the company with whom the meal is shared. In fact, there is more, much more—and this encompasses the lighting, cutlery, and dinnerware; the names of the dishes; a complex interaction among all the five senses; and finally the influence of more psychological conditions, such as memory and the state of one’s emotions.
A British psychologist, Charles Spence, and an expert in marketing and consumer behavior, Betina Piqueras-Fiszman, coauthored a book dealing with the multisensory science of food and dining. Spence is known for, among other topics, his work on the influence of sound on how food tastes—for example, our experience of meals on airplanes where there is a great deal of background noise. The book lifts the veil on a decade’s worth of scientific investigations of gastronomy. Such expressions as “culinary chemistry,” “molecular gastronomy,” “neurogastronomy,” and “modernist cuisine” have recently gained currency as part of a methodical approach to the study of gastronomy. In this volume, all the research is gathered together under the rubric of “the new science of the table.” Spence consistently uses the term “gastrophysics,” which was first used by the Danish physicist Michael A. Lomholt in about 2002–2003. The word really became mainstream after the first international conference on the subject held under the auspices of the Royal Danish Academy of Sciences and Letters in 2012.
According to Spence, creating the perfect meal depends on knowledge from fields as disparate as experimental psychology, design, neuroscience, sensory science, behavioral economics, and marketing, as well as culinary aspects of chemistry and physics. Many modern chefs and food producers now avail themselves of all this knowledge to fashion new, surprising, and memorable dining experiences. And it is not just a question of what goes into the mouth, but also what goes on in the brain.
The new branch of science, neurogastronomy, an expression coined by the Yale neurologist, Gordon Shepherd, is beginning to shape a scientific basis for understanding the meaning of the multimodal integration of the different sensory inputs in the brain. But according to Spence, more than that is needed to create a perfect meal: the dining table, the tablecloth, the cutlery and dinnerware, the names of the dishes and how they are presented, ambient sounds and lighting, as well as everything else that could collectively be deemed the esthetics of the meal.
Can it really be true that the weight, shape, and color of the cutlery and the dinnerware influence the taste experience? As shown by the studies conducted by Spence and his colleagues, the answer is possibly yes. Food that is eaten with heavy cutlery is interpreted by the diner as being of higher quality. Can it be correct that the sounds in the room also have an effect on taste? Again, studies have shown that a pizza is considered to have a more authentic taste if it is eaten while Italian opera music plays in the background and oysters are more enjoyable when sounds of sea and surf can be heard. Other experiments have demonstrated that if one is eating food out of a handheld bowl, one is likely to feel full earlier, and consequently, eat less from a heavy bowl than from a light one. Many are also aware that the noise in an airplane has a tendency to lessen the intensity of sour, sweet, and salty tastes, while umami remains unchanged. This is said to be the reason that so many passengers quite subconsciously order tomato juice while in flight, something they would rarely do when they are in a quiet bar on terra firma.
Spence documents how the way in which we name and describe a dish has a considerable influence on how we perceive its taste and whether we like it. The name of a dish can make it more attractive to the diner—twice as much money can be charged for an omelette à la norvégienne as for baked Alaska, even though the two dishes are identical. A cassoulet is also more tempting than a casserole. There is a long tradition of naming dishes made from offal and unusual animal sources in such a way as to redirect attention away from the actual raw ingredients. King eel certainly sounds more appetizing than smoked shark belly. Two Danish sensory scientists, Line Holler Mielby and Michael Bom Frøst, have also shown that the way in which a diner in a restaurant experiences and appreciates a dish depends on the information about it derived from the menu or given by the server. Their work has led to the surprising conclusion that a description of the techniques involved in the preparation of the dishes results in a more positive evaluation than a description of their sensory qualities.
Among the many other amusing discoveries set out by Spence and his colleagues is the significance of the actual material from which the plates are made, their color, shape, and size, as well as how the cutlery, glasses, and cups feel in the mouth. It would not be very appealing to drink red wine from a black tumbler or eat with a spoon that is covered in fur. The sound made by the cutlery also has an effect on taste perception. The sound of knife and fork on a porcelain plate is very inviting, whereas the feeling of placing a plastic champagne glass on the hard surface of a table is uninspiring.
Expectations of how the food will taste—for example, based on the name of the dish, its appearance, knowledge of the raw ingredients to go into it, earlier experiences of eating it, or the server’s description of it—and possible surprises have been shown to drive how we evaluate the dish. This is especially influential if our expectations are not met, for example, if the mouthfeel is not right even though the taste is identical. While a springy Caesar salad with fried bacon that crunches when we bite into it can be delicious, the same salad can be positively off-putting if it has had a trip through the blender.
