Coffee machine reviews: How we test
Our taste extraction expert Giles Hilton
It took almost 5kg of coffee and 20 litres of water to make the 640 measurements for the Which? coffee machine test.
Coffee machines taste testing
We asked Giles Hilton, head buyer for Whittards and a member of the Speciality Coffee Association, to act as our expert taster for all the coffee machines we've tested.
Giles has a palate that can discern the difference between espressos produced by different machines using the same ground coffee.
During our blind test he gave us his verdict on each machine’s espresso and cappuccino.
Though taste is a big part of this test, appearance, texture and aroma are also judged.
Espresso volume
An espresso should be no more than 30ml – any more could result in a watery coffee.
We found some coffee machines continue to drip even when the flow of espresso is switched off.
Time to make an espresso
We time how long you have to wait for one 30ml espresso, then how long the machine continues to drip.
Good coffee machines take less than 15 seconds to make 30ml and stop dripping.
Poor coffee machines can take up to 30 seconds to release 30ml and a further 30 seconds before they stop dripping completely.
Coffee temperature
To test the temperature of the coffee from the machines, we make an espresso then insert a digital thermometer into the centre of the cup.
We are looking for an average temperature no cooler than 60°C and no hotter than 88°C.
We use the cup warmers on machines that have them, but a warmed cup doesn't guarantee a hotter coffee.