How does an espresso machine work? A lesson in coffee making

You might be quite the coffee connoisseur. You know where your beans are grown, how they are roasted and exactly how the grounds reach you.

You also know how you like your coffee. But what about the espresso machine that makes it possible to get that cappuccino every day?

In this piece we will enlighten you a little on how an espresso machine works, so you can perfect your coffee making skills.

An espresso machine gets its name from the classic Italian shot of strong coffee called an espresso. A shot of espresso is basically water that is forced through coffee grounds in a specific way.

This is called pulling a shot and this is where an espresso machine comes in.

An espresso machines uses the parts of any cup of coffee, water, coffee beans (grounds) milk and heat. But it is in the way an espresso machine combines the ingredients that makes for a great latte, cappuccino or single espresso.

The water

The first thing an espresso machine needs to work well is water. Some machines will have a reservoir for the water. Others, especially high end models, can be connected directly to the water pipes of your home or restaurant.

The water in commercial and high end machines will then be held in a boiler and is heated by a coil inside this boiler. A sensor will measure the temperature here and turn the coil off when the water is heated as it should be.

This ensures the correct temperature is maintained for your coffee.

The coffee

The next element an espresso needs is coffee grounds. This is added in the portable filter and needs to be tamped down evenly.

This porta-filter then attaches to the machine at the group-head, with twisting and turning motion to lock it into place. This is so that the water and coffee are evenly distributed when the water moves through the coffee when the shot is pulled.

Some machines will have an additional attachment where you can grind your beans yourself. Some machines automatically grind the beans. You can also get separate grinders.

When you grind your beans just before making the coffee the flavor will be fresher and richer.

Heat it up

The machine will need to heat up next. This will vary depending on the type of machine and this can take a few minutes.

Like we said before, the water in the boiler needs to heat evenly and to the correct temperature. The machine will have an indicator like a light to show that the water has reached the correct temperature and that you can now pull the shot.

Some machines will also have cup warmers that you can use to warm the cup before you extract the shot. When you are ready to extract the shot, you will place the cup under the porta-filter.

You will now be able to extract the shot. Some machines will have buttons. Other older machines might have a lever.

A good shot should not produce a huge amount of coffee and will have a good creamy head or crema. This will take some skill and the way the coffee is put in the portafilter will have an impact on the shot that you get.

This is where you will be able to experiment a little with different coffee grounds and ways of using your machine.

The milk

Another element of an espresso machine is that you can froth milk for things like cappuccinos, lattes and so on. A good high-end espresso machine will have a wand or spigot for steaming and frothing milk.

Usually, you can use a separate pitcher or jug for the milk and then use it when you warm or froth the milk. You usually submerge the wand in the milk and the steam will heat the milk.

As you become more skilled with this you will also be able to create the perfect consistency.


In this piece we covered the main ways that most espresso machines work. Hopefully the process of getting to your next shot of espresso makes a little more sense now and you can use this knowledge when you prepare your coffee.