For example, Americans tend to rate drinks that are dyed red as more sweet in food perception studies (even when they taste identical to their clear or mismatched-colored counterparts), while green drinks are rated as more sour. There also seems to be evidence for an aversion to blue, a color often associated with spoiled food because of its resemblance to mold. A Korean study from last year found that participants preferred food with brighter, more saturated colors, in contrast to the color shifts that occur when food decomposes and becomes dull, and implied that this color preference might be the result of a “long evolutionary process.”
History has taught us that if you give people a product whose flavor doesn’t correspond with the right color, they enjoy it less. A successful change of Ivory liquid soap from milky white to clear in the early 1990s, for example, spurred beverage marketers to develop a range of clear products—Zima was born, Miller launched a clear beer, and Pepsi came out with Crystal Pepsi. All three of the products failed because their color didn’t match people’s expectations for how they were supposed to taste. “Even though Crystal Pepsi tasted the same as regular Pepsi, consumers perceived that it had a milder taste,” Garber says. “Moreover, neutral colors [in food products] confuse people, which typically makes people less likely to buy them.”
But the relationship between color and taste also has to be taken within a cultural context.
McDonald’s and other international chains have long adjusted their recipes and menus to cater to local tastes. Last year Thrillist dedicated a post to the best foreign McDonald’s products from around the world. (I’d personally love to try the deep-fried Camembert “cheese melt dippers” from branches in Ireland.)
With regards to the KURO burgers, Garber says, “Black in the U.S. simply doesn’t convey a favorable food meaning. It means charred or burnt or moldy or spoiled or inedible.” But in Japan, black is positively associated with food. Eva Hyatt, a professor of marketing at Appalachian State University, told New York Magazine that people in Japan are exposed to more black foods, including seaweed, bean paste-based foods, black walnut powder, squid ink, and other grey foods.”
In Japan, Hyatt said, local products tend to use subtle colors—like soft grays—in their packaging. On the other hand, bright colors are associated with foreign or Western food packaging, which might be considered too brash or loud. And while we associate death with the color black in the United States, the Japanese associate it with the color white.
Another study demonstrates that food attractiveness increases based on the perceived specialness of the ingredients. Researchers in Florence found that consumers were more willing to buy spelt, a species of wheat from Europe, when its label specified a smaller region of origin. So perhaps even if the color is initially off-putting, Western consumers might be less repulsed by the black burger once they know the ingredients that give it its gothic look. When I discovered that the buns and cheese get their color from bamboo charcoal and the sauce is made of squid ink and onions caramelized in soy sauce, I quickly changed my tune.
And there’s something to be said for the novelty factor as well. “A black burger in Japan is probably not going to make people react badly to regular Burger King burgers in the United States,” Garber says. “Everyone understands food is strongly culturally based.” Which is perhaps why we’re so fascinated by the black burger in the first place—it gives us a window into another culture, even if we ourselves won’t be trying them anytime soon.