Few people are likely to forget the first time they try shirako. The thought of eating cod sperm sacs may sound downright nauseating to the average Western diner, but those who pluck up the courage to try some are rewarded with an explosion of silkiness, more typical of a dessert than a savory dish.
It’s an example of the importance of mouthfeel: the physical sensations that determine our enjoyment of food. If our taste buds were the only guide we had, a fillet steak would seem equally delicious after a trip through the blender. Clearly there’s more to it than that: depending on what we eat, we expect our food to be crisp, tender, juicy, springy, gooey or smoother than … well, milt.
As biophysics professor Ole G. Mouritsen and chef Klavs Styrbaek note in “Mouthfeel: How Texture Makes Taste,” when diners in a restaurant send a dish back to the kitchen, it’s normally because the meat is too tough, the soup is too cool or the French fries have lost their bite. It’s not about how the food tastes, in other words, but about how it feels.
This is an area where Japan would seem to have a clear lead. The authors mention a study that identified 406 Japanese terms for texture, compared to the paltry 78 offered by American English. (A more recent survey in fact put the number even higher, at 445.)
Textures that were long banished from Western tables — and are only now making a comeback via molecular gastronomy and haute cuisine — have long been a fixture of Japanese food culture.
Mouritsen and Styrbaek’s previous book was an exploration of the so-called “fifth taste,” umami. In “Mouthfeel,” they take a similar approach, drawing on molecular science, culinary history and kitchen know-how to explain what’s going on when we chomp on pork crackling or a perfectly prepared apple pie.
The tactile experience that food evokes helps tell our brains whether something is OK to eat, and also whether it conforms to our expectations (think of soggy potato chips). This somatosensory input combines with our senses of taste and smell to create an overall impression of the food. Transforming raw ingredients through cooking, freezing or a range of other culinary techniques can dramatically affect the mouthfeel they produce.
Mouritsen and Styrbaek’s explanations go a lot deeper than that, of course, but you may need to have a scientific background to digest it all. Translated and adapted from Danish by Mariela Johansen, “Mouthfeel” strives to maintain a conversational tone but keeps tripping up on geek speak. One chapter starts with the summary: “All foods can be viewed as pliable, hierarchically constructed soft materials composed of many different types of molecules that relate to water in a variety of ways.” It’s not exactly Nigella Lawson.
The book is more engaging when it relates its scientific findings to familiar real-world uses. Our enjoyment of chocolate hinges on the fact that its melting point is just lower than the normal temperature of the mouth. Beef improves with aging because of enzymes breaking down the connective tissues and proteins, making it tender and juicy, while other chemical processes enhance the umami. Keeping bread in the fridge makes its starch grains crystallize faster — the same thing that happens when a freshly baked loaf left on the kitchen counter goes stale.
The authors demonstrate some creative uses of mouthfeel in a series of recipes, some of which are perhaps better suited to professional kitchens. A 22-step method for preparing the perfect duck breast, devised by celebrity chef Masaharu Morimoto, is presented with the sheepish caveat that “most people do not have a liquid nitrogen siphon as part of their kitchen equipment.” All the more reason to eat out, I guess.
For adventurous chefs and readers with a serious interest in gastronomy, “Mouthfeel” should prove a handy reference tool. But the principles it explains may assume greater importance in the future, too.
In their epilogue, Mouritsen and Styrbaek mention how mounting pressure on global resources will make it necessary to use our available food more efficiently. This comes after discussions earlier in the book of Soylent, the powdered “meal replacement” beloved of tech workers and venture capitalists, and “note-by-note cuisine,” a school of molecular gastronomy that involves constructing food entirely from chemicals.
It isn’t too hard to imagine a future in which scientists have figured out how to create perfect imitations of familiar foods, perhaps in the absence of the originals. No more Bluefin tuna? Never mind: here’s a lab-created version with a taste and texture that’s indistinguishable from the real thing.
Failing that, we could always look to some underexploited food sources. As the authors breezily note: “With their crisp, crunchy exoskeleton and softer innards, insects could quite easily be transformed into foods with a perfect mouthfeel.”
On second thought, maybe I’ll stick with shirako.