Taste: Surprising Stories and Science About Why Food Tastes Good (36 page)

YOU WILL NEED

2-cup liquid measuring cup

Boiling water

4 Lipton, PG Tips, or other black tea bags
¹⁸

3 glasses

Masking tape and markers

4 tablespoons sugar

⅛ teaspoon salt

3 spoons

1½ cups cold water

Saltine crackers for cleansing your palate

DIRECTIONS

1. Pour 13 ounces of boiling water over 4 tea bags in the measuring cup and let the tea brew for 10 minutes. You want to overbrew it so that the bitterness is pronounced.

2. While the tea is brewing, mark the glasses with tape on the bottom. Mark them:

• Tea

• Tea + S

• Tea + S + S

3. Put 2 tablespoons of the sugar in the glass marked Tea + S.

4. Put 2 tablespoons of the sugar and ⅛ teaspoon salt in the glass marked Tea + S + S.

5. Remove the tea bags after the 10 minutes and discard.

6. You should be left with 12 ounces of tea. Equally divide the tea among the glasses so that each glass gets 4 ounces of tea.

7. Put a spoon in each glass and stir until all the sugar and salt are dissolved.

8. Pour another 4 ounces of cold water into each glass and stir.

9. Taste all 3 teas and note how bitter and sweet each one tastes.

DISCUSS

1. You’ll notice that the tea (Tea) tastes bitter and the sweetened tea (Tea + S) tastes less bitter.

2. When you taste the tea with sugar and salt (Tea + S + S) you should notice that it is slightly less bitter than Tea + S but it’s also slightly more sweet. You’ve just experienced the superheroism of salt. It thwarts the bad tastes (bitter) and enhances the good tastes (sweet).

YOU WILL NEED

½ cup sugar, divided into ¼ cup measures

2 bowls

¼ teaspoon salt

Masking tape and markers

Knife

½ grapefruit for each person tasting

Saltine crackers for cleansing your palate

DIRECTIONS

1. Measure ¼ cup sugar into each bowl.

2. To one bowl, add the salt and mix well. With masking tape, mark this bowl on the bottom so you can tell which one has the salt in it.

3. Cut the grapefruits into wedges.

4. Sprinkle the cut surfaces of half of the grapefruit wedges with sugar.

5. Sprinkle the cut surfaces of the remaining wedges with the sugar and salt combination.

6. Give all tasters one wedge of each of two pieces of grapefruit from
the same piece of fruit
so that the only difference between the two is the salt.

7. Taste the wedge with sugar first. Note the level of sweetness and bitterness.

8. Eat a cracker to cleanse your palate.

9. Taste the wedge with sugar and salt next. Note the level of sweetness and bitterness.

DISCUSS

You’ll notice that the wedges of grapefruit with salt on them taste a tiny bit sweeter and less bitter. This is a result of the superheroism of salt.

I
n small amounts, bitter things like caffeine and alcohol can have very pleasant effects. At too-high doses they can be lethal, just like cancer drugs—which are bitter, by the way. When cooking with bitter ingredients, you want just enough bitterness to make the dish healthful and complex-tasting, but not enough to kill the dish. Bitter is, essentially, the chemotherapy of taste.

When food was scarce and cavemen were scrounging for it just to survive, they quickly learned not to eat too much of the stuff that made them sick. They developed conditioned aversions to things like certain bitter foods that upset the stomach or caused diarrhea. It’s likely that the foods that made people sick were high in phytonutrients, plant nutrients that have some medicinal benefits. When these bitter compounds are eaten in large quantities, they act like poisons. But it’s not pleasant to eat really bitter food in large quantities, so it’s a brilliant system: a food that’s so poisonous it will make you sick is also so bitter that you won’t want to eat a toxic amount of it.

Most people avoid bitter tastes. When we’re developing food at Mattson, we are constantly challenged to make (usually healthful) food taste less bitter so that more people will buy it. I can’t remember a project where our goal was an assertively bitter taste profile, though there is one food product that was created to taste extraordinarily bitter as a matter of life and death.

In the years between World War I and World War II, U.S. Army Quartermaster Captain Paul Logan was tasked with the job of stocking military bases, vessels, and soldiers with nutritious food. Everyday dining hall chow was easy. A bit more difficult was developing the field ration, a sturdy kit of food provided to soldiers for eating between bouts of combat. Most challenging was developing a form of nourishment for men who ended up in truly desperate conditions, such as those shot down in a plane or lost in a jungle. Logan wanted these men to have an emergency provision, capable of sustaining them for three days by itself, and ready to eat without preparation. It needed to be small enough and light enough—no more than four ounces—to fit in a soldier’s pocket, since space is at a premium in a plane, boat, life raft, backpack, or uniform. It also had to withstand extremes of temperature, from the frigid cargo bay of a plane and Northern European winters to the warmth of the human body wearing the pocket to the tropical heat and humidity of potential war zones such as the South Pacific islands.

The challenge was also to create a food that was bad-tasting enough that the men wouldn’t eat it nonemergency situations, but would save it for truly perilous ones. In Logan’s words, the food had to taste “a little better than a boiled potato.” The solution, he decided, was chocolate, and in 1937, Logan went to The Hershey Company. Sam Hinkle, the chief (chocolate) chemist at the company, accepted the job and created the D-ration, a chocolate bar that Hershey made exclusively for the United States military. Nicknamed the Logan bar, it was never going to win any culinary awards. With a melt point of 120°F, the Logan bar lacked the distinctive hedonic quality of other chocolate, the way it starts to melt the minute you put it in your mouth. In fact, some servicemen with bad teeth could barely eat the Logan bar at all because it was so difficult to bite into. But even hard, waxy chocolate was better than many other wartime provisions. Hinkle’s solution for ensuring that the Logan bar wouldn’t be traded for cigarettes or girly magazines was a stroke of genius: he developed perhaps the original high-cacao chocolate bar, so bitter it was universally despised—unless you were on a life raft or trapped behind enemy lines with nothing else to eat.

Sweet and bitter are the two Basic Tastes for which newborn humans have the most robust ingrained responses: sweetness signals that a food contains calories and bitter that it may contain poison. Most—but not all—poisonous foods are bitter. And most bitter things—but not all—are poisonous in high quantities.

Humans have only one or two taste receptors for sweet, but dozens of taste receptors for bitter because we need to be broadly and instantly aware of stuff that can kill us. Every time you taste something bitter, stop, count your blessings, and be thankful that your poison detection system is functional, as it’s the first line of defense for your survival. Tasting a food tells you very quickly whether you should swallow or spit, to avoid ingesting poison, which can kill you.

If you think of taste receptors as a police force, then bitter foods are repeat offenders flaunting their pharmacological power. Bitter swaggers. Bitter preens. It comes across as dangerous and is usually pronounced guilty before being proved innocent.

Many things in food taste bitter. Unlike the sour taste, which comes only from acids, bitter compounds include amino acids, peptides, esters, lactone, phenols, polyphenols, flavonoids, terpenes, methylxanthines (caffeine), sulfimides (saccharin), and salts. This is why we need so many different receptors. We need to recognize all bitter substances in order to avoid them at harmful levels.

Coffee is one of the most widely consumed bitter foods in the world, and most people think it’s the caffeine that gives coffee its characteristic bitter taste. In fact, only about 10 percent of the bitterness in coffee comes from caffeine. The rest comes from phenolic acids that result from the roasting process as well as the temperature, time, and method you use to brew the coffee. This makes sense, as decaffeinated coffee can be just as bitter as caffeinated. The bitterness in tea and chocolate also comes mainly from phenolic compounds other than caffeine.

Your genes influence whether or not a food tastes bitter to you. Remember the chemical PROP, used to test for sensitive taster types? Twenty-five to 30 percent of the population cannot taste it at all. The vast majority of people find it slightly bitter. A quarter to a third of the population finds it unbearable. There
are probably receptor genes for other bitter tastes (caffeine, quinine, and so on) that make people experience them differently. Individuals differ widely in our ability to detect bitter tastes, much more so than for the other Basic Tastes.

It’s possible that ancient tribes who lived in parts of the world where there was no threat from ingesting a certain type of bitter taste (tea leaves or broccoli, for example) might have lost the specific bitter receptor for it because it never got activated. One recent study asked adults to identify the predominant tastes they experienced in their diet for a period of a week. Not surprisingly, only 5 to 8 percent of the calories they ate were rated as bitter. This may mean that those of us who live in highly developed nations—where we eat very little in the way of bitter foods—might start to lose more of our bitter receptors. It won’t happen in the short run, but it could happen over centuries of cushy living and bitter-free eating.