Whether you're a keen cappuccino drinker, an avid mocha fan or just like your coffee as it comes, all barista-style drinks largely consist of two things – a shot of espresso and milk.
Of course the way you prepare the milk, and how much you add, changes which type of drink you end up with, but the espresso itself remains the same. This means pulling the perfect espresso shot is key to the best-tasting and most robust coffee.
- Espresso machine: Our favorite espresso machine is the Breville Infuser BES840X.
– Portafilter: The majority of espresso machines come with a portafilter and basket through which the coffee is filtered.
- Tamper: A tamper is a weighted accessory used to 'tamp' the coffee, which is a fancy way of saying compacting and flattening the grounds. These also come as standard with most espresso machine.
- Grinder: Some espresso machines have built-in grinders, such as the De'Longhi La Specialista Arte Evo (Amazon) or the Smeg Espresso Manual Coffee Machine (review). Alternatively, you can buy standalone grinders like the Krups Precise Stainless Steel Flat Burr Grinder (Amazon). Conical burr grinders are widely accepted as the best type of grinder because of their high-level of precision.
- Coffee beans: The best-tasting coffee comes from freshly ground beans. You can alternatively use coffee grounds but you won't get the same full-rounded flavor.
- Scales (optional)
"Coffee is possibly one of the most volatile products you’ve ever had the pleasure of working with," barista trainer Jon Skinner tells Top10Reviews. "It hates moisture, heat, light and time and they’re all on the move all of the time when making espresso." This can make the process seem daunting and difficult but it doesn't need to be.
Understanding a little more about how the best espresso machines work and what the process involves can improve your coffee-making skills and boost your confidence.
To help, I've run through each step below – from choosing and storing your beans to getting the perfect crema – and I get expert tips and advice from Jon, who is the UK's longest established independent barista trainer.
Choosing coffee beans largely comes down to personal taste and budget. As does your choice of milk.
The only thing to bear in mind is how you store the beans. As Skinner explains: "Coffee can go stale so it should be treated like bread. This means storing it in a dark, cool and dry place, and never in the fridge." Moisture and temperature can interfere with the taste of the beans and cause them to become stale and lose flavor.
Jon Skinner is the UK's longest established independent Barista Trainer. After several years of working within catering, Jon Skinner moved towards offering professional barista training services, and over the years has developed courses which are recognised by bodies such as The Speciality Coffee Association (SCA), Beverage Standards Association (BSA) and City & Guilds.
Quick steps for how to pull the perfect espresso shot
- Prepare: Clean and dry your espresso machine and accessories
- Pre-heat: Pre-heating the machine brings the water to the optimal temperature.
- Grind: Grind your coffee beans and place the grounds in the portafilter.
- Tamp: Level off excess grounds and tamp to flatten and compress the grounds.
- Lock and pull: Lock the portafilter into the group head and extract the shot into a cup.
- Steam (optional): Steam and froth the milk. This step only applies if you're making a warm milk-based drink.
I go into more detail about these elements below but, as a general rule the best conditions for making a great espresso shot are:
- 0.56 oz coffee grounds (16g)
- 25-second extraction time
- Water temperature between 195F and 205F (90C and 96C)
Step by step guide: How to pull the perfect espresso shot
1. Clean and pre-heat your machine
Before pulling your espresso shot, make sure your espresso machine, grinder and accessories are clean and free from any old coffee residues or oils. This not only helps get the best flavor from the grounds, but it helps extend the life of your equipment.
2. Pre-heat your machine
Next, preheat your machine. The temperature of the water used to pull the shot is the first thing can impact the flavor. "If the temperature is too low, the espresso will taste weak," says Skinner. "If it's too high, you'll burn the coffee and it will be bitter."
The sweet spot is between 195F and 205F (90C and 96C) and within this range the water temperature allows for a balance of acidity, sweetness, and bitterness. Many modern machines handle this step automatically and are set to deliver a temperature of 194F / 92C but if you're manually heating the water, you'll need a thermometer or similar.
3. Grind the beans
Getting the grind right is a skill in itself and this is where the most experimentation (and frustration!) can occur. The size of the grind – from fine to coarse – plays a direct role in how much pressure is created and how quickly the water moves through the grounds extracting the coffee. Both of which impact the flavor.
Choosing a high-quality grinder is a good place to start. "A domestic machine is only as good as the fineness of the grind you’re going to put into it," continues Skinner. "If you have a good-quality grinder you’re going to get closer to the perfect espresso."
From here there is no easy or quick way to know how fine or coarse your grind needs to be, sadly. This is because there are so many variables, from the type of beans you're using to the type of grinder, your basket, tamping pressure and the amount of coffee grounds being used. To master the grind, you may need to pull a few shots and check their consistency and taste in order to find the best size.
As a general rule, you want to grind 16g of coffee per espresso shot and the extraction should take 25 seconds. "The reason why we recommend a 25-second extraction time is because only 26% of coffee is dissolvable," explains Skinner. "In the perfect extraction, the optimum amount of 18-22% of these solids can be effectively dissolved in 25 seconds when there is 16g of coffee."
Again, most modern domestic machines are set up to deliver the optimal amount automatically but if you want to check, or be ultra-precise it's worth weighing the grounds before putting them in the portafilter basket.
Once the coffee has been added to the portafilter, use the tamper to level off the excess grounds and flatten and compress them into the basket.
You don't need to press too hard or compact the coffee too tightly. As Skinner says, "you just need to apply enough pressure until you feel the first signs of resistance."
5. Lock and pull
Once the grounds have been compressed, twist and lock the portafilter into the group head on the espresso machine. Place your cup underneath, select whether you want a single or double shot and extract your coffee.
This step only applies if you're making a warm milk-based drink.
Pour the milk into a jug and, using the steam wand on your espresso machine, steam the milk until it’s hot. You can alternatively heat the milk in the microwave or on the stove.
"The human palette burns at 159 F / 71 C," says Skinner. "We train baristas to heat milk between 148-158 F / 65-70 C so you can drink it straight away. Milk then scalds at 180 F / 82 C which ruins its taste."
To take the guesswork out of this, I recommend buying a pitcher with a built-in temperature gauge, such as this $11.99 Milk Frother from Amazon.
If you're using the steam wand as a milk frother too, move it up and down slowly in the milk so that it creates small bubbles. This jet of steam can be quite powerful so you can alternatively use a standalone milk frother or small hand whisk, like the $16.99 Bean Envy Handheld Milk Frother at Amazon, to create small, fine bubbles.
How do I know if my grind size is correct?
The best way to know if your grind size is correct is to keep experimenting until you find a taste and consistency you like because ultimately, the perfect espresso is the one you like best.
That said, there are few clues to look out for mid-pour that can help you refine the process.
- Pressure: While pulling your shot, check the pressure gauge found on the front of many modern machines. If the dial rises but falls, there isn't enough pressure. If it swings to the top of the bar, there's too much pressure. The dial should instead rise and stop within the optimum pressure bar usually found in the middle of the gauge.
- Size of the pour: The optimum extraction time should be 25 seconds. If you look at the pour and the tails of coffee coming out of the portafilter are too wide, it's extracting too fast. This means the grind is too coarse. If the coffee is dripping out, it's extracting too slow so the grind is too fine.
- Colour of the pour: In a well-extracted espresso, the colour of the tails will start off a dark brown color before lightening as the natural sugars are dissolved. If the tails don't change color, and particularly if they're too light throughout, the espresso isn't right and the grind will need changing.
- Crema: A well-extracted espresso will have a thick, brown crema on the top.
What is crema?
Crema is the creamy, caramel-colored layer of foam that sits on top of a shot of espresso and is created during the brewing process.
When hot water is forced through the coffee grounds, the heat and pressure emulsifies the natural oils in the coffee and traps tiny air bubbles. This creates a rich foam. The presence of crema is a sign that the coffee beans are fresh and the espresso has been extracted properly.
The composition of crema includes tiny coffee particles, oils, and gases (like carbon dioxide) and it adds to the overall flavor and aroma of the espresso, adding a slight bitterness and richness that balances the strong, concentrated coffee underneath.
The quality of crema can be influenced by a number of factors, including the type of coffee bean, the roast level, the grind size, the freshness of the beans, and the espresso machine's pressure and temperature.