That White Mug Makes Your Coffee Taste Bitter

Forget the latest pour-over trend. A much simpler method could improve the taste of your coffee: To make it less bitter, it may be that all you need to do is change the color of your mug, researchers say. Psychology researcher George Van Doorn got the idea for his experiment after a barista told him that people think their coffee is more bitter when it's in a white cup, he writes at the Conversation. He decided to test the notion, theorizing that brownness might be associated with bitterness in people's minds—and the contrast between white cup and brown coffee might reinforce this association, researchers explain in Flavour.

Van Doorn's team gathered 18 volunteers and had them drink from three mugs: a white one, a blue one, and a transparent one, Fast Company reports. The subjects reported that the coffee in the white mug tasted more "intense" than that in the other mugs, though it was all the same coffee. ("Bitterness" ratings and "intensity" ratings mirrored each other, Van Doorn notes.) An additional experiment, with 36 volunteers, used cups that all had the same shape but different colors; the results again suggested that color affected the perception of taste. Baristas, thus, "should carefully consider the colour of their mugs," Van Doorn writes. "The potential effects may spell the difference between a one-time purchase and a return customer." (Another way to get a different taste from your coffee: Order a beer latte.)