More than 2.25 billion cups of coffee are consumed across the globe each day, and its likely that many taste bitter.

Now, a new study suggests that coffee fans can make their drink taste sweeter by simply swapping¹ the colour of their cup.

Scientists claim that blue and glass mugs, which are popular in some coffee shops, reduce a coffee’s bitterness, without any need for sugar.

Researchers from Federation² University Australia and the University of Oxford³ set out to prove whether a barista’s claim - that coffee drunk from a white cups tastes bitter - was true.

They used 36 volunteers and three different coloured cups - blue, white and transparent⁴ glass - to investigate the claim.

In one experiment, the white mug enhanced the rated ‘intensity’ of the coffee flavour relative to the transparent mug, according to the study published in the journal Flavour.

Then, in a second experiment, coffee consumed from the white cup was found to taste less sweet when compared to the other coloured mugs.

While the blue cup made the coffee taste the sweetest.

The scientists believe that the colour brown may be associated with bitterness so that coffee in a white cup appears the brownest.

‘Our study clearly shows that the colour of a mug does influence the perceived taste and flavour of coffee,’ lead author Dr George Doorn of Federation University Australia, wrote in an article for The Conversation.

‘The effect of the colour of the mug on the flavour of the coffee reported here suggests that café owners, baristas, as well as crockery manufacturers should carefully consider the colour of their mugs,’ he said.

‘The potential effects may spell the difference between a one-time purchase and a return customer.’

The idea that colour can alter the taste of food and drink is not new.

A study published last year revealed that red, strawberry-flavoured mousse served on a white plate was rated as 10 percent sweeter and 15 percent more flavoursome than the same food presented on a black plate.