Taste: Surprising Stories and Science About Why Food Tastes Good (10 page)

The second taste dimension is intensity, or the degree of magnitude of a taste. I think of this as the How: How intense is the taste? How strong? How weak? Examples of this would be an extremely sweet tomato and a mildly sour one.

The third dimension he calls
oral location
, or the Where: Where in the mouth or throat is the taste perceived? Again, the best example of oral location is that most people detect sourness most strongly on the sides of the tongue. As you just learned, you can taste each of the five Basic Tastes everywhere. Where you perceive them to be the strongest is relevant but probably won’t affect your enjoyment of food.

The final dimension is the timing, or the When: When do you sense the taste? When does it start? When does it end? When is it the most intense? You may describe the timing of the tastes of homegrown cherry tomatoes as bitter and green at the beginning, as you bite through the outer skin. This would be called the
initial
or
up-front
taste. Then, as you keep chewing, you may experience sourness next. That would be the
middle
of the taste experience. And last, as you continue to chew and swallow, you may experience the sweetness. This would be the taste in the
finish
. The timing of taste is wonderfully illustrated by how differently we perceive the sweetness of sugar versus that of artificial sweeteners. Even though artificial sweeteners taste sweet, each one—sucralose, aspartame, saccharin, stevia, and so on—is detected in your mouth either faster or slower than sugar, and each lasts for a different length of time after the sweetness of sugar would have cleared from your mouth.

To really understand the way sweetness works for you, do the Sweetness Profile tasting exercise in the chapter on Sweet. I’ll explore this in more detail there.

The Four Qs of Taste: What, How, Where, and When

Adapted from: Paul Breslin,
Human Taste: Peripheral Anatomy, Taste Transduction, and Coding

Tasting food with your mouth is called
gustation.
This word comes from Latin and shares its origin with the word
gusto
. I love the simple redundancy of the term
eating with gusto
, which can also be translated as “gustation with gusto”—a good phrase to help you remember the scientific term for taste. Smelling aromas is referred to as
olfaction.

Gustation + Olfaction + Texture = Flavor

We’ll get into more later about each of these building-block tastes, as well as flavors, but for now, let’s talk about how your mouth works.

In 1999, when I was fairly new to my job at Mattson, I had a client in the vegetable business. The owners hired us to come up with exciting new vegetable appetizer ideas for their restaurant customers. After a few days of thinking about the assignment, I knew at least one of the ideas I wanted to create: cornmeal-crusted fried green tomatoes like the ones my father had cooked for us every summer weekend of my childhood. Typically, you make fried green tomatoes with unripe, green fruit that are harder and less juicy than ripe red ones. But because they’re usually sliced before they’re fried, the tomato slices are wet and flimsy and would be too difficult for our client to handle in the quantity needed for restaurants. As I worked through the idea in my head, it morphed and emerged as cherry tomatoes—much easier to handle. When we
couldn’t find green cherry tomatoes, I decided to start experimenting with red, ripe ones just to see how they might work out. We call this the
proof of concept phase.

Marianne Paloncy, one of our best chefs, called me into the food lab to show me samples of the inaugural batch of my creation. This is my favorite part of my job: seeing and tasting the physical manifestation of an idea. The little cherry tomatoes dipped in batter and lightly coated in cornmeal were adorably cute and promised crunch and flavor. They’d make a perfect restaurant appetizer.

Paloncy dropped a handful of them into the fryer basket and we waited two minutes for the cornmeal to crisp up on the outside, while the little spheres bobbed around in the bubbling oil. When she pulled them out of the fryer, they were glowingly golden brown. I couldn’t resist. As I reached my hand into the fryer basket, Paloncy started to speak, but before I could register her warning, I’d already popped a tomato and was pressing it against the roof of my mouth with my tongue. The 375°F frying oil, which had heated the copious water inside the red (ripe and juicy!) tomato, exploded in my mouth with excruciating force and volume. I opened up instinctively and spit out the entire thing, along with a huge flap of skin that I’d burned off the roof of my mouth. I could barely talk.
There goes my tasting career
, I thought.

Luckily, my damaged palate healed and the thousands of cells I’d scorched off my tongue and the roof of my mouth were replaced within two weeks, the normal amount of time it takes taste cells to regenerate. In fact, cells are constantly turning over from normal wear and tear. This programmed cell death makes perfect sense, since our taste buds are built to be abused, says Breslin: “If you could make a car that could regenerate parts for you, the thing you’d want to regenerate would be the treads on your tires.” You could say the lava-hot tomato burned the rubber off the roof of my mouth.

If I injured my mouth on a hot cherry tomato, I knew that beyond the liability concern, my client’s customers would have trouble getting the appetizer to diners within the small window of time between when the food came out of the fryer as scorching lava and before it cooled to mealy limpness. So I scrapped the cornmeal-crusted cherry tomato. But my accident gave me an appreciation for the mouth’s resilience and new insight into how important it is to have a mouth that functions properly. Much of the pleasure in eating comes from taste and texture, two things that were compromised (or painful) while I was healing. Still, I was shocked by how quickly my sense of taste came back. The mouth is
one of the most important tools we have to ensure our survival as a species. At the most basic level, if we don’t eat, we can’t nourish ourselves. And if we eat dangerous things, we can poison ourselves. If our sense of taste were to fail, we’d be at great risk.

When you put food in your mouth, your sharp
Homo sapiens
teeth come together to tear it into smaller pieces. Chewing, also called
mastication,
is what we do to prepare food for digestion. Chewing increases the surface area of the food, so that the enzymes in our body can start to release the nutrition from it. If you were to swallow food whole, you’d eventually digest it, but your digestive system would have to work much harder. One of the reasons we have such sharp teeth is to jump-start the process of getting energy from food. Another benefit of pulverizing the food into tiny bits is that we get to enjoy the flavor of it while we chew. The enjoyment of food reinforces our behavior and we eat again, which insures that we get proper nutrition.

Taste and the Two Ways We Smell

When you crush food between your teeth, tongue, cheeks, and the roof of your mouth (the soft palate), the aromas are released and get sucked up through your nose as you breathe. This flow of aromas from your mouth to your nose is called
retronasal olfaction.
This term is a mouthful (pun intended) so I’m going to refer to it as
mouth-smelling.
It’s different from the type of smelling you do with your nose when you sniff something that’s outside your body. Technically,
smelling through your nose while the food is still outside your mouth is called
orthonasal olfaction
, but I’m going to refer to it as
nose-smelling.

One important thing to remember about these terms is that in both cases, your nose is where the smell processing occurs. There are no olfactory receptors in your mouth. But in mouth-smelling (retronasal olfaction), your mouth is where the aroma molecules came from, on their way to being processed in your nose. In nose-smelling (orthonasal olfaction), the aroma molecules come in through your nose, and are processed in your nose. Please don’t ever say, “I smell with my mouth.” This statement is untrue. You smell with your nose from inside your mouth by means of retronasal olfaction.

When you see people slurping wine, they’re doing it to increase retronasal olfaction, or mouth-smelling. Slurping in air while tasting increases the flow of aromas, allowing you to smell and taste more—more quickly. While chewing with the mouth open is a social taboo in the United States, doing so would actually help us savor better because it would increase mouth-smelling. I will beam like a proud teacher if this book results in an eating public that slurps more unabashedly when eating and drinking. The more slurping you do, the more flavor you get.

You start to taste your food when the compounds in it change form in your mouth. With a crunchy food like a potato chip, you don’t start to taste until it mixes with your saliva and starts to break down. Saliva moistens dry food and helps release tastes and aromas. There are enzymes in saliva that break large molecules into smaller ones that have more flavor. The very makeup of saliva helps you taste.

The second way you taste is when a soft food like chocolate starts to dissolve from the heat of your mouth. One of the most seductive qualities of good chocolate is that it melts precisely at human body temperature, which provides a textural experience unlike any other food. This fact makes chocolate one of nature’s most perfect foods.

Adding moisture or heat—or both—to any food helps liberate volatile aromas from the food so you can experience mouth-smelling, which is where you experience most of the aromas from food. For instance, neither the potato chip nor the chocolate bar has much aroma on its own in its room-temperature state outside your mouth, even if you get really close and inhale deeply. It’s not until you put the food in your mouth that the moisture and heat make it become the crave-able food you know it to be.

The quantity and quality of saliva that you produce enhance your sense of taste. The autoimmune disease Sjögren’s syndrome causes the moisture-producing glands to shut down and patients often report that they experience a loss of taste. This is because they have a dry mouth, trouble chewing, and difficulty swallowing, all of which interfere with important contributors to the flavor of food.