What Is Espresso? How to Make Espresso at Home

Espresso is the foundation of most cafe drinks you know and love. Lattes, flat whites, cappuccinos, macchiatos, and Americanos all start with a shot of espresso. Yet despite its central role in coffee culture, espresso is one of the most misunderstood brewing methods. It is not a type of bean, not a roast level, and not simply "strong coffee". It is a specific brewing process that produces a concentrated, complex shot unlike anything else.

This guide covers what espresso actually is, how it works, its history, caffeine content, and how to pull a great shot at home with or without a dedicated espresso machine.

What Is Espresso?

Espresso is a concentrated coffee beverage brewed by forcing hot water at approximately 9 bars of pressure through a tightly packed puck of finely ground coffee in 25-30 seconds. The result is a small (30-40ml) but intensely flavoured shot with a thick, reddish-brown foam on top called crema.

Crema forms when pressurised water emulsifies the natural oils in the coffee grounds. It is a sign of a well-pulled shot and contributes to the rich, lingering aftertaste that makes espresso distinctive. A shot without crema, or with pale, thin crema, indicates a problem with grind, dose, or extraction.

Espresso is not defined by the type of bean or roast level used. You can make espresso with any coffee bean at any roast level. However, medium to dark roast Arabica blends are the traditional choice because they produce a balanced, sweet shot with good crema under pressure.

Espresso vs Regular Coffee

A Brief History of Espresso

Espresso was invented in Italy in the early 20th century. The word "espresso" means "pressed out" in Italian, referring to the pressurised brewing process, though it also carries a connotation of speed.

The first espresso machine was patented in 1901 by Luigi Bezzera, a Milanese manufacturer who wanted to speed up the coffee-making process for his workers. His machine used steam pressure to force water through coffee grounds in seconds rather than minutes. He called it the "Fast Coffee Machine".

In 1905, Desiderio Pavoni purchased the patent rights from Bezzera and commercialised the machine, exhibiting it at the 1906 Milan Fair. Pavoni's marketing skills brought espresso to a wider audience, and his name became closely associated with the drink.

The modern espresso machine was shaped by Achilles Gaggia in 1947. Gaggia's innovation was a spring-loaded piston that increased pressure from 1.5-2 atmospheres to 8-10 atmospheres, producing the characteristic crema for the first time. This is the pressure standard that all modern espresso machines are built around.

How to Make Espresso at Home

Pulling a great espresso shot requires attention to four variables: grind size, dose, tamp, and extraction time. Get these right and the result is a balanced, sweet, complex shot with a thick crema.

What you need: Espresso machine, burr grinder, kitchen scale, tamper, filtered water, freshly roasted coffee beans.

Step 1 - Dose: Weigh out 18-20g of coffee for a double shot (the standard in Australian cafes). A single shot uses 7-9g. Always use a scale for consistency.

Step 2 - Grind: Grind to a fine consistency, similar to table salt. The grind should clump slightly when pinched. This is the most critical variable. Too coarse and the shot runs fast and tastes sour. Too fine and it chokes the machine and tastes bitter.

Step 3 - Distribute and tamp: Add the grounds to the portafilter and distribute evenly with a finger or distribution tool. Tamp with firm, even pressure (approximately 15-20kg of force) to create a level, compact puck. An uneven tamp causes channelling, where water finds the path of least resistance and extracts unevenly.

Step 4 - Pull the shot: Lock the portafilter into the group head. Flush the group head briefly with water first to stabilise temperature. Start the shot and aim for 36-40g of liquid out in 25-30 seconds (a 1:2 ratio). If the shot runs faster, grind finer. If it runs slower, grind coarser.

Step 5 - Evaluate: A well-pulled shot should have a thick, reddish-brown crema, a syrupy texture, and a balanced flavour with sweetness, acidity, and bitterness in harmony. If it tastes sour, grind finer or increase dose. If it tastes bitter, grind coarser or reduce dose.

Making Espresso Without a Machine

A true espresso requires 9 bars of pressure, which only a dedicated espresso machine can produce. However, two alternatives produce a strong, espresso-style concentrate that works well as a base for milk drinks.

Moka pot: The most popular espresso alternative. Fills the lower chamber with water, packs the basket with fine-medium ground coffee, and heats on the stove until the coffee is forced into the upper chamber. The result is bold and strong, not quite espresso but significantly more concentrated than filter coffee. Remove from heat as soon as you hear a gurgling sound. For a full guide, see: How to Brew Moka Pot Coffee.

AeroPress: Use 18-20g of finely ground coffee with 60-80ml of water at 90-96 degrees Celsius. Steep for 30-60 seconds then press firmly. The result is a concentrated, smooth shot that works well as a latte base. The AeroPress does not produce crema but delivers excellent flavour.

Caffeine Content

A single espresso shot (30ml) contains approximately 60-75mg of caffeine. A double shot (60ml) contains 120-150mg. Despite its concentrated nature, a single espresso contains less total caffeine than a standard cup of filter coffee (80-120mg), because the serving volume is much smaller.

The caffeine in espresso is absorbed quickly due to the small volume and high concentration, which is why the effect feels more immediate than filter coffee. For guidance on safe daily caffeine limits, see: How Much Caffeine Is Too Much? Safe Daily Limits Explained.

Espresso-Based Drinks

Frequently Asked Questions

What makes espresso different from regular coffee?

Espresso is brewed under 9 bars of pressure in 25-30 seconds, producing a small, concentrated shot with a thick crema. Regular filter coffee uses gravity and takes several minutes, producing a larger, lighter-bodied cup. Espresso has more dissolved solids per millilitre but less total caffeine per serving than a standard cup of filter coffee.

What grind size is best for espresso?

Fine grind, similar to table salt. The grind should clump slightly when pinched. Espresso grind is the most sensitive of all brewing methods: small adjustments have a significant effect on extraction time and flavour. Always use a burr grinder for espresso.

How much caffeine is in a shot of espresso?

A single espresso shot (30ml) contains approximately 60-75mg of caffeine. A double shot contains 120-150mg. Despite being more concentrated than filter coffee, a single espresso contains less total caffeine than a standard cup of drip coffee because the serving volume is much smaller.

Can I make espresso without an espresso machine?

You cannot make true espresso (which requires 9 bars of pressure) without a dedicated machine. However, a Moka pot or AeroPress can produce a strong, concentrated coffee that works well as a base for milk drinks. The flavour is similar but lacks the crema of true espresso.

What is crema and why does it matter?

Crema is the reddish-brown foam that forms on top of a well-pulled espresso shot. It is created when pressurised water emulsifies the natural oils in the coffee grounds. Crema contributes to the rich flavour, aroma, and lingering aftertaste of espresso. Thin, pale, or absent crema indicates a problem with grind, dose, freshness, or extraction.

What is the correct espresso ratio?

The standard espresso ratio is 1:2 (coffee in to liquid out by weight). For a double shot, use 18-20g of ground coffee and aim for 36-40g of espresso out in 25-30 seconds. This ratio produces a balanced shot with sweetness, acidity, and bitterness in harmony.