Espresso

Espresso is a small, concentrated coffee made by forcing hot water, at about 9 bar of pressure, through a tamped puck of finely ground coffee. It takes around half a minute and gives you a short, thick, intense shot with a layer of crema on top. It’s also the base for most café drinks. Here are the standard numbers, how to pull a good shot at home, how to fix one that tastes wrong, and where the espresso machine came from.

The short version

• Hot water at about 9 bar forced through a puck of fine, tamped coffee.
• A good start: 18 g of coffee in, 36 g of espresso out (1:2), in about 25–30 seconds.
• The SCA training range: 7–10 g for a single, 14–20 g for a double, a 1:1.5 to 1:2.5 ratio and 20–30 seconds.
• Grind fine, then adjust the grind until it tastes right: that’s dialling in.
• You need an espresso machine and a good grinder. Moka pots and AeroPresses make strong coffee, but not true espresso.

How does espresso work?

An espresso machine pushes hot water through coffee at high pressure. The coffee sits in a metal basket held by the portafilter, packed down into a firm, level puck. The machine’s group head sends water through a shower screen, and the pressure forces it through the puck. That’s why espresso needs a much finer grind than any other method: the fine grounds create the resistance the pressure works against.

What are the standard espresso numbers?

There are two well-known definitions:

	SCA training range	Certified Italian espresso (INEI)
Dose	7–10 g single, 14–20 g double	7 g, plus or minus 0.5
Ratio	1:1.5 to 1:2.5	Not set by ratio
Volume in the cup	Not set by volume	About 25 ml, plus or minus 2.5
Time	20–30 seconds	About 25 seconds
Pressure	Not specified	9 bar

The Italian Espresso National Institute’s definition describes a traditional Italian single. The SCA range covers doubles too, measured by weight. A common starting point for a double is 18 g in, 36 g out.

What do you need?

• An espresso machine that reaches about 9 bar
• A burr grinder that can grind fine and adjust in small steps; this matters as much as the machine
• Scales to weigh the coffee and the shot
• A tamper that fits your basket
• Fresh coffee; espresso shows up stale coffee more than any other method

What grind size should I use?

Fine, finer than for any filter method, but not powder. Exactly how fine depends on your grinder, your coffee and your machine, so the grind is what you adjust to get the shot right.

How do you pull an espresso shot, step by step?

1. Warm everything up. Let the machine heat fully, with the portafilter locked in. Flush a little water through the group head.
2. Grind and dose 18 g into a double basket, by weight.
3. Distribute and tamp. Break up clumps, level the coffee and tamp firmly and evenly.
4. Lock in and start straight away, with your cup on scales.
5. Stop at about 36 g in the cup, ideally around 25–30 seconds after starting.
6. Taste and adjust one thing at a time.
7. Knock out the puck, rinse the basket and flush the group.

Brew mode on this page times the shot for you.

How do you dial in espresso?

Dialling in means adjusting until a coffee tastes right. Keep the dose and the target yield the same, and change the grind:

What happened	What it tastes like	Try
Ran fast, well under 20 seconds	Sour, thin, salty	Grind finer
Ran slow, well over 30 seconds	Bitter, harsh, dry	Grind coarser
Spurting, or a pale stream early on	Sour and bitter at once	Distribute and tamp more evenly: that’s channelling
Right time, still sour	Sharp, under-extracted	Pull a slightly longer shot, e.g. 1:2.2
Right time, still bitter	Harsh, over-extracted	Pull a slightly shorter shot, e.g. 1:1.8

Time is a guide, not a rule. If a shot tastes great at 33 seconds, it’s a great shot.

Single or double espresso?

The difference is the dose and the basket. The SCA training range is 7–10 g for a single and 14–20 g for a double. Use the basket that matches your dose: an under-filled or over-filled basket makes an even puck harder.

Where does the word espresso come from?

It’s Italian. Caffè espresso comes from esprimere, from the Latin exprimere, “to press out”. The word also carries the sense of coffee made expressly for you, to order. The popular story that it simply means “fast coffee” isn’t the accepted explanation.

A short history of the espresso machine

• 1884: Angelo Moriondo of Turin patents a steam-driven coffee machine for brewing in bulk. It wasn’t sold beyond his own businesses.
• 1901–1902: Luigi Bezzera of Milan applies, in December 1901, for a patent on improvements that brew a single serving to order, through a portafilter; it’s granted in June 1902.
• 1903–1905: Desiderio Pavoni buys Bezzera’s patent in 1903 and founds La Pavoni in 1905, making one machine a day in a small Milan workshop.
• 1940s: Achille Gaggia’s spring-piston lever machine (on sale from 1948) pushes water through the coffee at far higher pressure than steam could, giving espresso with crema as we know it.
• 1961: Faema introduces the E61, designed by Ernesto Valente, with a motor-driven pump instead of a lever. Its name comes from the solar eclipse of that year, and its group head design is still widely used.

Espresso vs other brewing methods

	Espresso	Moka pot	AeroPress
Pressure	About 9 bar	Roughly 1–2 bar, from steam	Hand-pressed, low
Grind	Fine	Fine	Medium-fine
Crema	Yes	Little or none	Little or none
Kit	Specialist machine and grinder	A stovetop pot	A hand press

General guidance only. Espresso machines run at high pressure and temperature: always follow the instructions for your machine, and never remove a portafilter mid-shot.

Espresso variations

The same machine makes several other shots, each with its own guide:

• Ristretto: the short, concentrated shot, about 1:1.
• Lungo: the long shot, with more water through the coffee.
• Café allongé: the French long coffee.
• Turbo shot: a fast, coarser modern style.
• Blooming espresso: pre-infuse, pause, then extract.
• Soup shot: a very low-pressure, long-ratio style.

Other ways to make espresso include the lever espresso machine and the manual espresso press.

Explore every pressure method in the pressure chapter.