Scientists claim to have discovered secret to perfect espresso

Researchers say dash of water added to beans before they are ground creates more consistent, tastier coffee

The key to making a perfect espresso has been argued over by generations of coffee snobs. Now a group of scientists say they have the answer and have singled out the secret ingredient - and it comes before the grind even begins.

Researchers have discovered that a dash of water added to coffee beans before the grinding process creates a more consistent and tastier espresso, which they say will help baristas and industrial coffee brewers overcome a major hurdle.