Most of us think of espresso as a hot, high-pressure ritual. Finely ground coffee goes into a machine, boiling water is forced through it, and in about 30 seconds we get a concentrated shot with crema, aroma, bitterness, body and caffeine.

As someone from Colombia, I like to think coffee is in my blood – and I’m proud to come from a country known for producing some of the best coffee beans in the world.

So perhaps that’s why I have spent a lot of time in my laboratory with my team asking a simple question: does espresso really need hot water?

Our new research suggests the answer may be no.

Low energy, full strength

We have developed what we call an ultrasonic espresso: a room-temperature brewing process that uses high-frequency sound waves to extract the flavour, oils, aroma and caffeine from coffee grounds. The result is an espresso-strength coffee made in under three minutes, but needing far less energy than the conventional method.

Saving up to 75% of energy by not heating the water is a minor benefit for home users or small........

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