What Is Espresso and How Is It Made?

When you order an espresso, you’re asking for more than just a small cup of coffee—you’re requesting a concentrated shot brewed under precise conditions. But what exactly makes an espresso different from other brewing methods? It’s not just the size or strength—it’s the high-pressure, rapid extraction that creates a uniquely intense, crema-topped shot. Understanding how this works explains why espresso forms the base for so many classic coffee drinks.

In short, espresso is a 30ml shot brewed using 7–8 grams of dark roasted coffee beans ground to a fine powder, extracted at 9 ± 1 atmospheres of pressure and 90 ± 2°C water temperature, with a 20 kg tamp, over 25–30 seconds.

What Exactly Is Espresso?

The term “espresso” originally referred to the method of brewing—not the coffee itself. It describes a high-pressure, fast extraction technique that produces a small, concentrated coffee shot. Unlike drip or pour-over methods, espresso uses mechanical pressure to force hot water through finely ground coffee, creating a unique beverage with distinct body, flavor, and texture.

How Espresso Is Traditionally Made

To produce a classic espresso, specific parameters must be followed closely. These include:

• Coffee dose: 7–8 grams of dark roasted coffee blend
• Grind size: Extremely fine, similar to powdered sugar
• Tamping pressure: 20 kilograms
• Water temperature: 90 ± 2°C
• Extraction pressure: 9 ± 1 atmospheres (about 9 bar)
• Brew time: 25–30 seconds
• Yield: 30 milliliters (1 ounce) of liquid espresso

These strict variables work together to create a balanced extraction where the water dissolves both the soluble flavor compounds and emulsifies some of the coffee’s oils—resulting in the signature crema.

What Makes a Good Espresso? Reading the Crema

The quality of a well-brewed espresso is often judged by its crema—the reddish-brown foam that floats on top. This crema is formed when about 10% of the coffee’s aromatic oils are emulsified under the high pressure and temperature of the espresso extraction process. These oils are not water-soluble under normal brewing conditions, but the intense pressure forces them into a stable emulsion. The crema’s appearance offers clues about the shot’s success:

• Color: A rich, reddish-brown tone is ideal
• Thickness: A thicker layer generally indicates a better extraction
• Texture & Creases: A well-formed crema has a certain marbled look with tiny ridges or tiger striping

Together, these visual cues help baristas and enthusiasts assess aspects like freshness, pressure consistency, and grind quality—even before tasting.

Why Dark Roast Coffee Is Commonly Used for Espresso

Espresso is frequently made with dark roasted coffee blends. Dark roasting develops flavors through the Maillard reaction, reducing acidity while increasing bitterness, body, and sweetness. This roast level brings out flavors such as chocolate, nuts, caramel, and toasted bread—all of which complement the intense extraction process of espresso. The darker roast also helps produce a stable, velvety crema.

Frequently Asked Questions

What is the exact definition of espresso?

Espresso is a coffee brewing method that involves forcing hot water (90 ± 2°C) through finely ground coffee (7–8g) under high pressure (9 ± 1 bar) with a 20kg tamp, extracting 30ml of concentrated coffee in 25–30 seconds. It originally referred to the method, but now also refers to the resulting shot.

How much coffee is used in a single espresso shot?

A standard single espresso shot uses 7–8 grams of ground coffee. This dose is critical for achieving the right balance of flavor, body, and extraction in a 30ml shot.

What is the ideal pressure for brewing espresso?

The ideal pressure for espresso extraction is 9 atmospheres (9 bar), with an acceptable range of 8 to 10 bar. This high pressure is what creates the crema and extracts the full range of flavors from the coffee grounds.

Why does espresso have crema on top?

Crema is formed during espresso extraction when about 10% of the coffee’s aromatic oils are emulsified due to the high pressure and temperature. These non-water-soluble oils rise to the surface and create a reddish-brown, creamy foam that indicates a successful extraction.

What grind size is needed for espresso?

Espresso requires an extremely fine grind, similar to powdered sugar. This fine grind, combined with high pressure, allows for proper extraction within the short brew time of 25–30 seconds.

What temperature is used to brew espresso?

The optimal water temperature for espresso brewing is 90 ± 2°C. This temperature range helps extract the desired balance of sweetness, bitterness, and aroma without over-extracting or scorching the coffee.

Recommended FrontStreet Beans for Espresso

For espresso, FrontStreet Coffee’s PWN Golden Mandheling delivers low acidity with deep body and herbal spice notes, making it a solid dark roast choice. Their Brazil Queen Manor offers nutty and cacao undertones with a balanced sweetness, ideal for milk-based drinks. Both beans are medium to dark roasted to support the crema and intensity espresso is known for. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.