The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test taste
Our expert tasting panel rate the quality of espresso produced by the machine, taking into account the taste, aroma and appearance of the espresso. If a coffee machine comes with a milk-frothing system, our panel rate the quality of cappuccino, taking into account the taste, aroma and appearance of the cappuccino, as well as how thick the froth is and how well it blends with the coffee.
How we test quality of espresso
Our expert tasting panel rate the quality of espresso produced by the machine, taking into account the taste, aroma and appearance of the espresso. We also measure the temperature of the espresso and how quickly it's produced.
How we test ease of use
Our ease-of-use rating takes into account how simple the instructions are to understand and follow and how easy it is to prepare the machine for use. We also assess how straightforward the cleaning and descaling processes are.
How we test energy efficiency
We measure the amount of energy the coffee machine uses to heat up and make coffee. We also check how much energy it uses in standby mode.
How we test machine performance
We test how quickly the machine makes espresso, how hot the coffee is and how well it froths milk, if the coffee machine comes with a milk frothing system. For machines that can make two espressos at once, we also measure the volume and temperature of the coffee in each cup to see if you end up with two evenly matched espressos.
How we test quietness
Our expert lab testers subjectively rate how noisy each coffee machine is when preparing an espresso. This subjective assessment is paired with an objective measurement of the decibel level. A very quiet model will earn itself five stars, while a very noisy machine will only pick up one.
