How we test coffee machines

Every coffee machine that we test is put through the same standard tests to let us gauge quality, and performance.

While coffee is a subjective experience, the machines themselves will make a difference. We run standardised tests to help ensure our recommendations can be compared.

Test environment

For all coffee machines that take coffee beans or ground coffee, we roast our own coffee. We use a Gene Cafe Roaster with Fairtrade Peruvian coffee, using a medium-light roast: we want to preserve a lot of the original flavour so we can better compare individual machines.

For bean-to-cup machines, we use the full bean. For manual espresso and filter machines, we grind the coffee using a Lelit William PL72 grinder. For pod machines, we use a variety of the manufacturer-provided capsules.

How we test each type of machine

All machines are tested for the quality of their coffee.

Espresso machines: the aim is to produce the best quality shot of coffee possible. For manual machines adjustments include varying the grind size, adjusting the tamp and, where possible, adjusting the temperature.

Bean-to-cup machines: we adjust the grind, coffee strength and, where possible, temperature.

We measure the temperature of the final shot, as espresso should be somewhere around 65C: hot, but cool enough to drink almost immediately. When judging quality, we take into account the quality of the crema: it should be oily, thick and a reddish-brown colour, lasting for several minutes. We then taste each shot, looking for the more subtle notes in our test coffee.

Filter machines: we use the manufacturer-recommended amount of coffee, adding more or less after the first batch depending on whether we think it’s too strong. All coffee is then taste-tested.

Pod machines: are tested with the same criteria, but we can’t make adjustments to the way that coffee is produced. Depending on the pod machine, we’ll test with a variety of capsules, taking in the full array of drinks that can be made.

Milk frothing

Milk frothing is an essential part of any espresso machine (manual or bean to cup). Where there’s a manual steam wand, we froth milk manually, using a milk thermometer to standardise the finished temperature.

We use semi-skimmed milk and will make several jugs of coffee to get used to the way that a machine delivers steam. At the end, we tap the jug and swirl to get rid of big air bubbles, and then pour a cappuccino. The aim is to have a finished drink that’s one-third coffee, one-third milk and one-third milk foam. The foam should be neatly textured, and tightly packed with the appearance wet paint; too many bubbles shows that something has gone wrong.

For machines that use an automatic milk frother (or even powdered milk) we let the automated process do the heavy lifting, but we look for the same results as for our manual method.

Ease of use and maintenance

How easy a machine is to use is important. We look at the available options, how clearly laid out the controls are and how easy it is to change settings.

All coffee machines need maintenance, so how easy they are to look after is very important. We look at how simple the daily tasks are, including emptying drip trays, rinsing and, depending on the machine type, emptying pod/use coffee grounds.

We also look at how each machine can be descaled and cleaned, giving those machines that make this easier higher scores.

Scoring and verdict

After all the tests are complete, we score the product using the criteria outlined in the criteria mentioned here. We first check to see if the product’s performance matches the manufacturer’s claims, and that all the features work as expected and advertised.