Espresso
Espresso uses high pressure to force hot water through finely ground coffee, extracting a rich, concentrated shot.
What Is Espresso?
Espresso originated in Italy. It uses around 9 bars of pressure to force hot water through about 18 g of finely ground coffee in 25–30 seconds, yielding roughly 36 g of concentrated coffee. In Italian, "espresso" suggests something made quickly and expressly for you — it was developed so coffee could be brewed fast and to order.
A Brief History
In the early 20th century, Italian inventors began brewing coffee with steam pressure. In the 1940s, Achille Gaggia introduced a spring-piston lever machine capable of much higher pressure, producing the first modern espresso topped with crema. Electric pump machines later replaced levers, and espresso spread worldwide with café culture.
Defining Characteristics
- Crema: the golden foam on top, formed by CO2 and oils emulsified under high pressure
- Intensity: highly concentrated flavor
- Full body: silky, weighty mouthfeel
- The foundation: the base for lattes, cappuccinos, and other milk-based drinks
Brewing Parameters
| Parameter | Recommended |
|---|
| Dose | 18–20 g |
| Yield | 36–40 g (about 1:2) |
| Grind size | Extra fine |
| Water temperature | 90–94°C |
| Extraction time | 25–30 seconds |
| Pressure | About 9 bar |
Dialing In
Measure yield in grams with a scale rather than by milliliters in the cup — crema makes volume very misleading.
- Sour, thin, running fast: under-extracted — grind finer or extend the shot
- Bitter, astringent, running slow: over-extracted — grind coarser or shorten the shot
- Change one variable at a time: grind size is usually the first lever
Common Problems
- Channeling: if the puck is uneven, water rushes through gaps, giving sourness and astringency at once. Distribution tools and even tamping help
- Beans too fresh: freshly roasted beans hold too much CO2 for stable extraction — rest them 7–14 days
Common Espresso Variations
- Ristretto: shorter extraction, more concentrated (ratio about 1:1–1:1.5)
- Lungo: longer extraction, more water (ratio about 1:3)
- Doppio: a double shot of espresso
- Americano: espresso topped up with hot water
- Latte, cappuccino, flat white: espresso with milk in different ratios and textures
Choosing Beans
Traditional Italian blends use medium to medium-dark roasts for chocolate and caramel notes. Many specialty cafés now pull medium-light single origins for a juicy, fruit-forward shot — in that case raise the water temperature and extend the shot slightly.