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Taste
1
Taste
I was in Philadelphia in a minivan heading to the restaurant Buddakan with five researchers from Monell, a nonprofit research institution focused on uncovering the scientific mysteries of taste and smell. Seated behind me was Marci Pelchat, whose expertise includes food cravings and food addiction. One of the chattier scientists from Monell, she pointed out landmarks during our quick ride. Reading Terminal Market, Pelchat told me, houses downtown Philly’s version of a farmers’ market, although it has become a tourist destination.
“But I think you can still get pickled tongue there,” she said.
“Beef tongue?” I asked, remembering it from the Jewish delis of my youth, where the sight of a five-pound cow’s tongue would make me squeal.
“Kosher tongue?” inquired Bob Margolskee, a Monellian who studies taste at the molecular level.
“Yes, you know, cow tongue that’s been cured like corned beef. You slice it to make sandwiches,” said Pelchat. “I bought a whole one there to use as a prop for a demonstration on taste that I was giving a while ago. It’s an amazing way to point out the papillae on the tongue. Just like ours, only bigger.”
“I’m in need of a tongue,” chimed in Michael Tordoff, a researcher at Monell who studies, among other things, our taste for the mineral calcium.
“You mean a human tongue?” I asked. “For research?”
“Yes,” he answered. Human tissue samples are apparently hard to obtain.
“I’m not just looking for any tongue,” said Tordoff, “I’m looking for a fresh tongue.”
“Some people at Monell just lop off their own tastebuds,” Margolskee told me as we arrived at the restaurant. When you dine with sensory scientists, disturbing visual images about their work accompany the meal.
The first thing I learned when I got to Monell was how the improper use of the word taste sends sensory scientists into a bit of a tizzy. I was corrected no fewer than five times for using the word taste to mean the combination of taste, smell, and texture. Science demands proper terminology, but since I’m not a scientist, I don’t use their jargon. I speak and write in plain English, as you do, and I say things such as I can’t taste anything when I have a cold and my nose is stuffed up. Yet my taste system, as the scientists pointed out, is most likely perfectly functional. It’s my sense of smell that is compromised when I have the flu. Taste is just the tip of the iceberg, since most of what we think of as taste is smell. Some of the food odors we smell come from sniffing the food when it’s under our nose (outside the mouth). But most of the aromas we perceive when we eat are released in the mouth and reach the nose through the mouth.
When you eat something new, you taste it for the first time, although you’ll also smell, feel, and touch it. When someone asks you whether you like a food, he asks if you like the taste of it, but what he really wants to know is if you like its combination of smell, taste, texture, appearance, and sound. Yet taste has become the default word for the experience of eating food—in both noun and verb form—because we do (using correct scientific terminology) taste with our mouth.
You instinctively know that what you experience when you eat is just as dependent on your nose as on your tongue. In fact, research has proved that every other sense—sight, hearing, touch, and smell—can influence what you taste as well. But you don’t eat with your nose. You don’t put food into your ears or eyes. When the system is working the way it should, you put food into your mouth.
This causes us to connect flavor to the mouth because it’s the place we taste, the place where taste sensations are initially sparked. But only a small portion of what you experience as flavor happens on the tongue. Linking the entire experience of food to the mouth, though understandable, is what causes the confusion.
There are only five tastes that humans can detect using their mouths, alone. Technically speaking, if it’s not one of the five Basic Tastes, it’s not a taste at all. Everything else we experience in the mouth is either an aroma or a texture. The combination of these three characteristics—tastes, aromas, and texture—is correctly called flavor. The tastes in a tomato include sweet, sour, and umami (the taste described as savory or brothy). The aromas in a tomato include grassy, green, fruity, musty, and earthy. The texture depends largely on how ripe the fruit is and how it has been prepared, from juicy, firm, raw tomatoes to tender, soft, simmered ones. And the overall flavor of a tomato is what you know of as a tomato, the whole gestalt.
To appreciate, firsthand, how profound the difference between taste and smell is, I suggest you try the exercise called Separating Taste from Smell, which is at the end of this chapter. Plug your nose, and while holding it shut, put a jelly bean in your mouth and start chewing. After a few chews, you’ll easily detect the two Basic Tastes evident in it: sweet and sour. Once you release your nostrils, the aromas of it will spring forth: tropical, cherry, pear, melon, buttered popcorn. The flavor of the jelly bean you’ve chosen is the combination of the two Basic Tastes, the signature aromas of whatever flavor you’ve chosen, and the texture, chewy-tender.
Of course, you don’t have to use a jelly bean to isolate the taste from the aroma of a food. Use a cherry tomato or fig or strawberry and you’ll experience the same thing. With your nose pinched shut, you’ll detect very little of the characteristic flavor of what’s in your mouth. You’ll get only sweet, sour, bitter, salt, or umami. Release your nostrils, breathe, and then you will get the aromas of tomato, fig, or strawberry.
In Taste What You’re Missing, I’m going to use plain English and say, “when you taste a tomato” even though I may be talking about the total multisensorial experience of eating a tomato. But I will also use (and recommend the common usage of) the term savor as a verb when the word taste is scientifically incorrect. For example, “When you savor a tomato, you get the green aroma first, followed by the basic tastes sweet and sour.” We usually think of savoring something as consuming it with delight. But Merriam-Webster defines the verb savor as “to have experience of,” so savor really does work in sentences where the word taste is incorrect.
The linguistic tendency to use the word taste to mean flavor is not an idiosyncrasy of the English language. University of Pennsylvania professor Paul Rozin asked bilingual speakers of nine languages to provide synonyms for the words taste and flavor. They were given a dictionary to see if they could find better words. And then they were educated on the difference between the Basic Tastes and aroma. In seven of the nine languages (Spanish, German, Czech, Hebrew, Hindi, Tamil, Mandarin Chinese), it appears that this same idiosyncrasy exists, so that if it goes in the mouth, it’s tasted. Only Hungarian and French seemed to have words that hinted at a distinction between the concept of taste versus that of taste plus aroma: what you know now is flavor.
The word for flavor in French is, not coincidentally, saveur.
Sensory Snack
Taste and smell are the only two senses we confuse. Imagine someone saying, “When I heard that Renoir, I was really moved.” or “I like to watch the radio.” It just doesn’t happen.
The Five Basic Tastes
Once you learn the five building blocks of taste, you will see how they work in harmony with the other senses and start thinking more critically about what you’re tasting. Four are familiar to most people: sweet, sour, salt, and bitter. The fifth, umami (pronounced ōōa-mä’mē, which rhymes with “who MAH me”) is a newer term, imported from Japan, which is loosely translated as savory, brothy, meaty, delicious, or round. Umami refers to the savory taste of certain proteins that make a good beef steak or soup stock taste so rich and full. If you were to take all the salt out of chicken or beef broth, you’d be left with umami. It isn’t a taste we crave on its own. It really needs to be paired with salt. More about this complicated taste later in the book.
These five Basic Tastes are the only tastes that we can detect using our sense of taste without support from any other sense. For now, think about them as the five tips of a star. Throughout the book I’ll be using the star as a tool to help you form a visual representation of how inextricably linked each taste is with the others, as well as how important all five senses are when you’re experiencing food.
The Taste Star: The Five Basic Tastes
The Sensory Star: The Five Senses
I use the star shape because it’s perfectly balanced, which is how I think about the five tastes: there isn’t one taste that’s more important than the others for making food taste good. Not every food should contain all five Basic Tastes. And not every food should contain all five in equal proportions. Take wine, for example. Most wines contain the sour and bitter tastes. Some wines are sweet. But almost no wines are salty. And this is a good thing: it doesn’t belong.
Sensory Snack
Salted wines exist in the world of food manufacturing. For good reason.
Adding salt to wine makes it undrinkable, which is exactly what you want when you’ve got huge vats of it sitting around a food manufacturing plant; you want to make it as unattractive to your employees to imbibe as possible. The government classifies salted wine differently from unsalted wines so that companies such as sauce manufacturers can use salted wine in their formulas without a liquor license.
When you’re cooking or seasoning a dish, it is important to make sure that one taste doesn’t dominate the others, whether all five tastes are present or not. When one taste (or aroma) dominates, we say that the dish is out of balance; the way the star would be if one of the points were bigger than the others. A wine that tasted salty would definitely be out of balance.
When one taste is out of balance, it throws off the whole food, dish, or drink.
It’s fairly easy to recognize a dish that’s out of balance from too much salt or bitterness, because it will be unpleasant (as a salty wine would be). What’s harder to identify is a dish with too much umami or savoriness. When you become more familiar with umami, you’ll be able to tell when there’s too much of it. Let’s review the five Basic Tastes very broadly; then for each Basic Taste we will go into more depth in its own chapter.
Sweet
Sweet is the term we use for simple carbohydrate compounds such as sucrose, more commonly known as sugar. Almost universally, people describe sweet tastes as pleasant. While sugar is the purest form of this taste, lots of other things naturally taste sweet, such as fruit (which contains fructose) and dairy products (which contain lactose). Sugar is a quick source of calories, so we are genetically predisposed to seek out sweet things.
Sour
We use the term sour to describe the taste of acidity. Lemon juice and vinegar are two of the most prevalent sources of sourness in food; both liquids are high in acid (citric acid in the case of lemon juice, acetic acid in the case of vinegar). Acidity is usually pleasant but can quickly become unpleasant at high levels; a squeeze of lemon can brighten up the flavor of grilled fish or a glass of iced tea, but straight lemon juice is mouth-puckeringly unpleasant. Some people, however, love the extreme sourness of lemons so much that they suck on lemons repeatedly. This can cause the enamel on their teeth to erode if they do it often enough for a long enough period of time. In a pretty nifty design—compliments of Mother Nature—most people find that foods with tooth-rotting acid levels are too sour to eat.
Some acids make foods and beverages taste fresh and bright, whereas other acids indicate spoilage and can trigger instant rejection of those foods. Acids also help preserve some foods, such as pickles.
Bitter
Individual tolerance varies more widely for bitter foods than for any of the other Basic Tastes. Bitter foods can be very unpleasant on their own if they are not balanced by other tastes and flavors. Coffee, tea, and red wine are common bitter beverages that can be delicious when carefully crafted. Most compounds with medicinal effects have a bitter taste—some at low levels, some at high levels. Our ability to taste bitterness has evolved to help us identify substances that can be toxic. Caffeine, for instance, is extremely bitter. It has a very real, well-recognized medicinal benefit—stimulation—but at high levels it can be toxic. Many poisons taste bitter and their medicinal effect—death—is one you probably want to avoid. That’s why it makes sense that humans have a complicated, distrustful view of bitter tastes.
Salt
Salt is the term we use to describe the taste of sodium ions. The most common form of salt is sodium chloride, which we add to food while cooking or sprinkle on at the table. Many foods naturally contain sodium, such as seafood and celery. Salt is critical to life, but we cannot store excess sodium in our bodies, so we are programmed to seek it out in the form of food. In modern times, getting just enough sodium in our diets—without excess—has proved to be a bigger challenge than getting too little. Regardless of how much sodium we consume, our craving for salt is natural—and critical to survival.
Umami
Umami is the most difficult taste to explain because the term is not commonly used outside the world of food or outside Japan, where the term originated. Umami is the taste of glutamates—amino acids that are present in some foods such as beef and mushrooms. The best-known umami-rich compound is glutamic acid—or glutamate—which occurs naturally in some foods such as mushrooms and seaweed. Monosodium glutamate (MSG) is the salt of glutamic acid and this form is often added to foods as a seasoning. We sometimes describe umami as tasting meaty, savory, satisfying, or full. Think of the difference between raw ground beef—which has little umami—and a well-cooked hamburger, which has lots. Other savory foods that are high in umami are cooked tomatoes and the king of umami: aged Parmesan cheese.
The Geography of the Tongue
How do we actually taste these five Basic Tastes? One possibility is that different regions of the tongue process different tastes—as on this map, some version of which you almost certainly saw in elementary school.
The taste map of the tongue. Be careful how you interpret this!
The map shows the geography of the tongue and which area corresponds to which ta...