London - It's a claim which is bound to cause a stir among coffee lovers.
Experts say what you sip the drink from affects its flavour – with a rough cup leaving a bitter after-taste while the same coffee tastes sweeter from a smoother vessel.
Scientists in Brazil – the world’s biggest coffee producer – ran tests involving experts and regular drinkers. They found that the "haptic" – or touching – experience of what people were drinking from made a big difference. More than 230 people took part in the research, with half of them experts – including professional coffee graders.
They drank high-grade Brazilian coffee from a smooth porcelain cup and also used a mug made of white ceramic with a rough finish on the outer and inner walls. Both were a similar shape and weight.
Psychologist Dr Fabiana Carvalho said: "The coffee was perceived as sweeter when tasted from a smooth-surface cup. The coffee was rated as more acidic from the rough cup.’ She added: ‘These results demonstrate that haptic cues influence the judgment of basic tastes as well as mouth-feel attributes in specialty coffee.
"The cup in which the coffee is served is an essential element in terms of turning the consumption of specialty coffee into a truly engaging multi-sensory experience."
The research team at the University of Sao Paulo wrote in the journal Food Quality and Preference: "Both quality-graders and amateurs judged the after-taste as significantly more dry when tasted from the rough rather than from the smooth cup.
"The results demonstrate for the first time that “sensation transference” from the haptic feel of cup texture can significantly affect the quality of specialty coffee after-taste."
The team also claimed that drinking high-quality coffee rivals a fine wine. Wine has an estimated 600 to 1 000 volatile aromatic compounds to create its complex flavours, but there are more than 1 200 in coffee.