Right now, I am drinking black coffee from a ceramic brown mug. I’m not sure where it came from, but it looks like one of those bottom-shelf mugs you might find collecting dust in a thrift store. Normally this is something I wouldn’t notice. But as it turns out, the color of your mug could affect your perception of how strong your coffee tastes.
A new study published in the journal Flavour was conducted by psychologist George Van Doorn at Monash University in Melbourne. The goal was to test if the color of your cup changes the way your coffee tastes. “The idea behind this study came about serendipitously,” he writes. “A barista once told me that when coffee is consumed from a white, ceramic mug, it tastes more bitter than when drunk from a clear, glass mug.”
The psychological impact explored here concerns contrast—what the coffee looks like. When you’re drinking from a white cup, the coffee certainly looks browner. This could unconsciously suggest to you that it tastes more intense, more flavorful. A separate study from 2011, for example, found that participants who ate strawberry mousse from a white plate as opposed to a black plate tended to rate their dessert 5% sweeter when they were, in fact, the same dish.
A similar concept may apply to coffee. In his first experiment, Van Doorn enlisted 18 tasting volunteers and used three colors: a blue mug, a clear mug, and a white mug. The goal was to assess perceived variations in coffee flavor without telling participants that they were, in actuality, drinking down the same stuff.
The white mug, in particular, seemed to make the coffee taste stronger—more coffee-like—than the clear mug. Van Doorn writes:
The white mug enhanced the perceived “intensity” of the coffee flavour relative to the transparent mug. Our hypothesis was that a crossmodal association between brown and bitter exists and that bitterness, and possibly other attributes, would be enhanced by the colour contrast.
“Intensity” was graded on a handful of 0-100 scales: sweetness, bitterness, aromatic strength. The process was then repeated in a second experiment, with 36 volunteers, but this time, the shape of the mugs were identical. The results were similar to the first experiment.
Van Doorn’s conclusion? “Café owners, baristas, as well as crockery manufacturers should carefully consider the colour of the mug and the potential effects that its colour may exert over the multisensory coffee drinking experience.”
I guess it’s time to get a new mug.