Coffee machine reviews: Features explained
How coffee machines work
We reveal what all the different parts on coffee machines do, in our interactive coffee machine chooser tool. And below, we explain the different types of coffee you can make.
An espresso maker makes coffee with a more intense caffeine hit than a filter machine or cafetière.
An espresso is about 25 to 30ml of strong black coffee, and should have a good crema – a golden froth that is rich, firm and creamy enough to float on top of your coffee until you finish.
Most espresso machines have a steam pipe (sometimes called a milk frother or steamer nozzle) for hot milk and foam, so you can make lattes or cappuccinos using the espresso as a base.
Espressos form the base for milky coffee drinks like cappuccino
Espresso coffee machines
Espresso coffee makers can be used with ground coffee, coffee beans or coffee capsules.
A motor-driven pump, forces water through a thermo block, which heats it quickly, then forces it through the ground coffee under pressure, usually between 10 to 19 bars of pressure.
Most have a large, removable tank you can fill directly from the tap or in situ with a jug, so you can make enough espresso for all your dinner party guests before it needs refilling.
Look out for a cup warmer, which uses the heat from the thermo block, to gently warm cups before they're needed.
Using coffee in an espresso machine
There are three main coffee formats to choose from. Some models can take several types: use our compare features and prices tool to find a machine that works with your favourite coffee format.
Ground coffee
Ground coffee is the most commonly used type. You can choose from a huge variety of blends and, for some coffee lovers, the espresso-making ritual is an intrinsic element of espresso enjoyment.
When using ground coffee, preparation is everything – discover exactly how to make a great coffee, and get expert advice, in our video to making perfect espresso and cappuccino.
It takes a little effort to clean up the coffee grounds afterwards, but they can be composted.
Our expert recommends a finely ground blend of Arabica beans with a little Robusta, as espresso machines use a brewing method that's a little brutal for pure-blend coffees.
Freshly-ground beans offer great flavour
Coffee beans
Freshness is the key to a good espresso, so purists will choose fresh coffee beans over ground.
The oils in roast coffee beans begin to evaporate immediately after grinding so using freshly ground beans is the best way of capturing the most flavoursome essence.
If you want the freshest and best coffee you can get, one option is to invest in a bean-to-cup machine - an espresso machine with a built-in bean grinder.
These grind the beans for you, then compact the newly ground coffee inside ready for brewing.
The main advantage is superior flavour because the beans are freshly ground. This type of machine is also a good option if you don’t want the faff of measuring and tamping ground coffee yourself.
The drawbacks are that the grinding action is noisy and that these machines tend to be far more expensive than those that use ground coffee.
Some models allow you to use both beans and ground coffee. If you don't want to buy a machine with a built-in grinder, you can buy a separate coffee grinder, These cost from around £20 to £150.
Coffee capsules (Nespresso, Gaggia Caffitaly, Dolce Gusto)
Coffee capsules are hermetically sealed pots of ground coffee that are inserted into an espresso machine. The machine pierces the capsule and forces hot water through to make espresso.
Capsules stay fresh for up to nine months, which is ideal if you're an occasional espresso drinker. Like pods, they contain just enough coffee for one shot and are mess-free.
Most machines are only compatible with the coffee capsules produced by their manufacturer. So Nespresso machines use Nespresso capsules, Dolce Gusto machines use Dolce Gusto capsules and so on.
Freshly-ground beans offer great flavour
Recycling coffee capsules
Most coffee capsules are made up of several layers of materials, meaning they can’t be recycled, and many are thrown away after use, which can be wasteful.
However, Nespresso offers recycling facilities for its Nespresso capsules. Some stores will collect used capsules and recycling bags can be ordered along with capsules, which drivers will collect (when full) while delivering your next order. For more information visit the Nespresso Ecolaboration website.
Additional features
Cup warmers
Some coffee machines have a cup warmer. But these can take around 20 minutes to heat up, so unless you're making coffee for six people or more, the best way to warm your coffee cups is with hot water while you’re priming the machine.
To discover exactly how to prime your coffee machine, watch our video guide to using a coffee machine
Portafilters and filter baskets
Coffee espresso machines that use ground coffee will come with one or more removable baskets that you fill with ground coffee.
Filter baskets are available in different sizes: the two standard baskets are for single and double shots but some also have a third basket for use with ESE pods.
The portafilter is the handle and holder of the filter basket. Some portafilters have a plastic flap in the handle which folds over to hold the loose filter basket in place when emptying it of the hot, used ground coffee.
Sometimes, rather than being loose, the filter baskets can be so tightly fitted into the portafilter, it makes removing them tricky. This is something we pay attention to during our testing.
Rewind our coffee machines live event
Which? experts were joined by top coffee connoisseur, Whittard's Giles Hilton, and Bob Payman, who's been selling and servicing machines for 15 years, for a live chat. We were kept busy with your questions on the best coffee makers and how to perfect your espresso making.
Missed it? Log in to replay the Q&A in full at Which.co.uk/coffeelive.
- Discover which models are Best Buys in our coffee machine reviews
- Is worth paying £120 for a coffee machine? Find out in our coffee machine FAQs
- Prefer filter coffee? We reveal how to buy the best filter coffee maker