The Scarlet Batter

Why our aversion to artificial coloring makes no sense.

Dessert may be a guilty pleasure, but red velvet cake feels like a crime. The recipe alone stains our conscience with 2 ounces of artificial color—that’s two squeeze bottles of FD&C Red No. 40 emptied in your mixing bowl. Some bakers wear gloves to keep the shameful dye off their skin; others scrub at the damned spots with lemon and nail polish remover. It’s enough to make a foodie blanch.

A recent article in the New York Timesreveals that professionals are just as likely to wring their hands over the growing demand for artificially colored, glowing-red cake. “I can’t bear the thought of all that food coloring,” proclaims the executive chef of the Waldorf-Astoria, where red velvet cake was once thought to have originated. Like other angst-ridden chefs described in the piece, he has toiled to develop an all-natural alternative, using beets or cherry juice for color.

But why should a dose of Red No. 40 turn Betty Crocker into Hester Prynne? Ask a gourmand and you’re likely to hear three specious answers. First, Epicurean: Artificial color tastes bad. Second, Hippocratic: It’s bad for your health. And third, Platonic: It makes food unnatural.

The belief that artificial color impregnates a dish with unnatural taste can be dismissed most easily: The industrial dyes have very little flavor of their own. (Don’t believe me? Give yourself a taste test, like the one we conducted at Slate last week.) Natural colorants, on the other hand, often add their own unintended flavors to a dessert. A little turmeric might gussy up yellow curry, but you’d never want it in your yellow frosting. You might prefer the taste of an all-natural red velvet cake—but only if you happen to like your chocolate with a subtle hint of beet. The relative blandness of artificial color proves to be its greatest virtue. 

While you might be disgusted to learn that some FD&C-approved dyes are derived from coal tar, that doesn’t mean they’re toxic. The Delaney Clause bans additives at the first sign of cancer in lab animals, even when they show no clear risk to humans. (The scare over Red No. 2 in the 1970s was based on one such finding.) And natural foods like wine, cheese, yogurt, and bread can also cause cancer in lab animals. Some evidence suggests that artificial colors can cause allergic reactions or contribute to hyperactivity in children. But the color-free “Feingold diet” has produced questionable results as a treatment for ADHD. In any case, natural dyes can cause reactions, too, and their origins may be as much of a gross-out: Sausages, ice cream, and Campari, for example, are routinely colored with an allergenic scarlet made from the crushed bodies of the cochineal insect. *

If the artificial colors are as safe as natural ingredients and they don’t taste bad, then why should we avoid them? The gastronome might argue that the chemical dyes impart a color that’s unappetizing on its own terms. The garish brilliance of red velvet cake has no referent in nature; it’s disgusting because it’s fake. Natural dyes, on the other hand, can make food look wholesome and real, by restoring our ingredients to their natural state. If a stalk of rhubarb loses its rosy hue in the saucepan, we add it back by boiling the skins. But to take this distinction seriously, you have to accept the outdated idea that a food has a “natural color” to begin with.

For instance, the fruits we call “oranges” are often green when they’re fully ripe. (They turn orange on the tree only when they’re exposed to cold weather or bathed in ethylene gas.) The oranges you buy at the supermarket may look natural, but there’s a good chance they’ve been coated with Citrus Red No. 2. Likewise, we’re all familiar with the faint, yellowish color of pure butter. (Margarine manufacturers were once penalized for conniving to make their pale-white substitute look more like the real thing.) But thanks to a loophole in the FDA’s labeling rules, that wholesome shade is often the result of added dyes. (Click here for more on the “natural” color of butter.)

Even a completely artificial product like soda pop can appear more or less fake depending on its color. During the clear-drink marketing fiasco of the early 1990s, consumers turned their backs on Crystal Pepsi, despite efforts to promote its healthy, natural appearance: “Right now, nature’s inventing better stuff than science,” said the ad campaign. Coca-Cola followed suit with Tab Clear, and Miller came out with a beer that looked like seltzer. But the change in color made consumers uncomfortable. Some complained of a medicinal aftertaste, as if the new products were more artificial than the originals.

People even imagined a faint citrus flavor in Crystal Pepsi, since it resembled 7-Up. But the clear color of lemon-lime drinks is no more natural than the caramel brown of a standard cola. (Imagine a glass of lemonade: The citrus oil turns water cloudy.) In fact, the uncola was brown when it debuted in the 1920s; its caramel color was removed only a few years later.

Our intuitive understanding of natural color has dissolved into a murky set of learned associations that affect the way we experience food. A study in the current issue of the Journal of Consumer Research describes a test involving two glasses of Tropicana orange juice, one of which was darkened with artificial food coloring. Subjects ascribed a sweeter taste to the more brightly colored juice, irrespective of its sugar content. Another experiment fooled a panel of oenophiles: Tasters used the language of red fruits to describe a rigged-up bottle of white wine spiked with food dye—it had notes of raspberry, black currant, and cherry. 

Science tells us that the rosy tint of a rhubarb pie is vital to its flavor. But this doesn’t mean there’s an innate relationship of deliciousness between pink and rhubarb—it merely suggests that we’ve grown accustomed to the pairing. Likewise, the red in red velvet cake might someday taste as natural and delicious as the yellow in butter, the brown in Pepsi, or the orange of oranges.

That’s why chefs engage in all sorts of mischief to mask the natural colors of prepared food. We acidulate apples and artichokes to prevent brown stains, and shock our greens to keep them bright and zesty. Grenadine adds some red to a gray slop of poached strawberries; squid ink makes a beige risotto black; a few threads of saffron turn rice a jaunty yellow. Chef Thomas Keller feels no shame in admitting that he makes a flavorless colorant from ground-up spinach, parsley, and watercress, which he adds to herb sauces to “heighten visual impact.” We’re hardly inclined to keep our all-natural ingredients in their native states, and yet we shun artificial colors for being “fake.”

At the same time, some of the world’s most famous chefs experiment with industrial ingredients that let them alter the texture and shape of their foods beyond recognition. Ferran Adrià of Spain’s El Bulli employs xanthan gum to give puréed mango the texture of an egg yolk. At WD-50 in New York, Wylie Dufresne uses transglutaminase (or “meat glue“) to make noodles almost entirely of shrimp meat and chicken breasts into perfect spheres. It’s easy to imagine how Adrià or Dufresne might use a pallet of chemical lakes to paint his foods to exquisite effect. But it seems like even these freewheeling molecular gastronomists stop short of artificial color. What are they afraid of?

* Correction, March 14, 2007: This piece originally described the cochineal beetle as a source of natural red dye. The dye comes from the cochineal insect. Click here to return to the corrected sentence.