Taste: Surprising Stories and Science About Why Food Tastes Good (37 page)

At Mattson, we always test the prototypes we develop with consumers. They unabashedly let us know right away if we’re kidding ourselves that we’ve developed a truly Big Idea. We recruit children to taste kids’ prototypes and if they make faces like the one above, we go back to the drawing board. For us, this face is the sign of failure. But another company is actually aiming for this reaction to its product, denatonium benzoate, which goes by the trade name Bitrex. In fact, the company uses a picture like this one to market the product. Bitrex is not just really bitter; it’s Guinness World Record bitter. Bitrex is the most bitter substance known to man.

Imagine you’re developing a household product, such as a liquid soap, that you want to smell like strawberries. If you were smart (because you read this book) you would make it a beautiful bright red color to further communicate that it smells of strawberry, knowing that our eyes are critically important to the perception of aroma. The problem is that bright red, shiny liquids look delicious to young children, who, if they get their hands on this soap and smell strawberry, will put it in their mouths to see if it tastes as good as it smells. If your soap also happens to be poisonous, this poses a real problem. Bitrex to the rescue! Because Bitrex is colorless, odorless, and completely harmless, a tiny amount of it in your strawberry soap will ensure that any child who puts it in his or her mouth will spit it out immediately. And make the bitter face.

Bitter is also added to antifreeze, which has a notoriously sweet taste, in the form of denatonium benzoate, now a critical ingredient in the formula to make it unappealingly bitter to kids and animals. If you’re trying to quit biting your nails, you can buy products containing denatonium benzoate to paint onto the tips of your fingers. A few naughty nibbles at your cuticles and you’ll be dashing to the bathroom to rinse your mouth out.

For my birthday one year, Roger offered to cook me anything I wanted for dinner. Normally, I do most of the cooking in our household, mostly because I like to, but also because Roger doesn’t. He grills meat much better than I, and he can sear a mean lamb chop, but although he’s a passionate eater, he is just not very interested in cooking.

So I thought I’d make it easy on him for my birthday. I requested that he procure (not cook) crabs, one of the comfort foods from my childhood. Cooking live crabs is a task best left to professional cooks, those born and raised in Maryland, and the nonsqueamish. Roger is none of the above. Because we live in California, flying my beloved blue crabs across the country would have required a lot of advance planning and politically incorrect air travel for the doomed crustaceans. So I decided to rough it and settle for our local Dungeness, with a side of oven-roasted potatoes and a simple salad to round out the meal.

While Roger was shopping, someone gave him the excellent advice to make the salad with bitter greens to balance the sweetness of the crabmeat.
As a non–green food eater, Roger took this quite literally. He picked out one fresh head each of frisee, endive, and chicory. And just for good measure, he added a fourth lettuce: a Treviso radicchio so bitter I went to the store the next day to find out what it was (so I could avoid it in the future). Roger tossed the salad with tree-green extra virgin olive oil, freshly squeezed Meyer lemon juice, salt, and pepper. We sat down to eat and I took a big forkful of the beautiful produce on my plate. That was my first and last taste of the salad.

“Don’t you like it?” Roger asked, more than a little crestfallen. “Oh, it’s perfect,” I said. “Bitter. Very bitter. Just what you were going for. Maybe a little too bitter?” I offered as I flushed my mouth out with water and a big hunk of bread before returning to the crab. It was simply too much of a good thing.

That’s the rub with bitter foods. Just like chemotherapy, they play a very important role in small doses, requiring restraint so as not to overwhelm. What Roger might have done was build a salad from sweet greens like butter lettuce or mâche, and used a small amount of the bitter greens as supporting actors. We can tolerate few bitter foods as the star of the show.

As much as people love coffee, most who drink it doctor it up. Seventy-five to 80 percent of the population perceives coffee as bitter, from just a bit to off the charts. Yet the 25 to 30 percent of the population who are Tolerant Tasters may experience black coffee as lacking bitterness entirely. You know these people. They’re the ones drinking espresso as if it tastes like water.

Adding Taste Star counterpoints like milk and sugar, to coffee, balances the bitterness with other Basic Tastes. In fact, the daily act of adding milk and sugar to coffee is one of the best examples of how we intuitively balance tastes without thinking. If you use a dairy product like 1%, 2%, whole milk, or cream, in addition to lowering the bitterness of the coffee, you’re also adding fat to it. Fat adds a desirable, creamy mouthfeel that coats the tongue and makes the coffee taste less bitter. The way this works is that the bitter compounds in the coffee are diluted into the fat phase of the milk. This makes them less able to reach bitter taste receptors. When you consider using fat as a counterpoint to bitter, it’s interesting to note that fat is also a contender for Basic Taste status, as we’ll see later in the book.

One of the goals of the Taste Star is to help you think about
all
tastes when you’re cooking, not just the ones that come easily to mind (salt, sugar, sour). When you taste a dish, envision the star, and think about what’s missing by considering each point in the star. Does it need salt? Should it be sweeter? Should it have a touch of acid? Would umami make it richer? Does it want bitterness? Most people try to avoid bitter. But the talented chef knows how to use bitterness to add complexity to a dish. By
complexity
I mean adding another counterpoint, as well as making the resulting food more challenging than it normally is. Our lazy palates easily accept sweet foods, but sweetness with a “just about right” level of bitterness makes you stop and think,
Hmmmmmm, there’s something interesting going on there.
Bitter plays this complexifying role.

Bitter also makes extremely salty or sweet foods less so. In other words, it suppresses salt and sweet.

I used this knowledge one night while cooking up a batch of barbecue sauce on my stovetop. I had smoked a beef brisket (unsuccessfully, due to my lack of patience), which took a few more hours than I’d planned for. I was frantically trying to get everything finished and ready to serve before our dinner guests arrived. I stopped following the measurements on the barbecue sauce recipe and started improvising. When I finally got the sauce reduced to a viscosity that I liked, I dipped my spoon in to taste. Too sweet! With very little time to get this sauce right, I considered the Taste Star, which led me to ingredients on the other four points. I added a few dashes of soy sauce to give a bit more umami, some seasoned rice vinegar to pump up the sourness without adding much aroma (because the volatile aroma of lemon, for example, doesn’t belong in an American barbecue sauce). I tasted again. Still too sweet. And now, thanks to the soy sauce and seasoned vinegar (which both contain sodium), too salty! The only taste that was going to get me out of this mess was bitter. I opened my pantry. Bitter. Bitter. I needed something bitter that would marry well with my tomato, honey, and vinegar sauce. I grabbed the container of unsweetened cocoa powder and voilà! The bitter cocoa powder balanced my otherwise sweet, sour, salty, and umami sauce. Perfect Taste Star harmony.

We’re learning more about bitter every day, but we already know that this Basic Taste usually indicates some kind of pharmacological function. Aspirin is bitter and has well-known pharmacological benefits. Ibuprofen is bitter and functions as an anti-inflammatory drug. Tea is bitter and high in antioxidants.

Many vegetables such as greens, and fruits such as pomegranates and cranberries, taste bitter because of polyphenols, flavonoids, isoflavones, terpenes, and glucosinolates, lumped together under the term
phytonutrients
. And guess what? These are the compounds responsible for giving produce the ability to help lower the risk of cancer and heart disease. Imagine if we could enhance the phytonutrient content of our foods to make them even more healthful. Just as The Tomato Project’s Harry Klee wants to create the most delicious yet hearty tomato, we could use traditional breeding techniques to create plants that have more of the healthful compounds. Unfortunately, it’s difficult to do this without increasing the bitterness, which people don’t want to taste.

Cranberries have a unique type of mouthfeel, called
astringency
or
tannin
, which gives the sensation of having your tongue dried out. In fact, cranberries are so tannic, astringent, and bitter that they are barely tolerable in naked form. Dried cranberries (or Craisins, the brilliant trademark that Ocean Spray coined) are infused with sugar to balance the bitterness that’s naturally occurring in the fruit. The compounds that make cranberries bitter may be responsible for their function in helping avoid and alleviate urinary tract infections.

Many tannic or astringent foods are bitter, but tannin and astringency are not experienced with a bitter taste receptor. They act on the trigeminal nerve
that carries touch information to the brain. Although we generally refer to our perception of tannin and astringency as tasting bitter, physiologically speaking it’s a feeling, not a taste. To experience the tannic astringency of grape skins as bitter, do the Feeling Tannic? exercise at the end of the chapter.

Many people also confuse the Basic Tastes bitter and sour, probably because many sour foods are also bitter. Grapefruit and cranberry are two great examples. Both have an assertively sour taste with some strong bitter notes, especially in the pith of the grapefruit and the skin of the cranberry. Sour tastes sharp and pungent. Think of vinegar or lime juice. Bitter tastes unpleasant. Think of unsweetened espresso, tea, or chocolate. Because these are both Basic Tastes, it’s really hard to describe them without using the words sour or bitter. To experience the two, I suggest you do the sensory exercise Differentiating Bitter from Sour at the end of the chapter.