Here are some key facts about espresso:

1. Origin: Espresso originated in Italy in the early 20th century. The name “espresso” means “pressed out” in Italian, referring to the method of brewing under pressure.
2. Brewing Method: Espresso is made by forcing hot water (about 90-96°C / 194-205°F) through finely-ground coffee under high pressure (around 9 bars). This process takes 20-30 seconds and produces a small, concentrated shot of coffee.
3. Size and Strength: A typical espresso shot is about 1 ounce (30 ml) and is highly concentrated, offering a strong, bold flavor. While it has more caffeine per ounce than regular coffee, the small serving size means a single shot contains about 63 mg of caffeine, compared to 95 mg in an 8-ounce cup of drip coffee.
4. Crema: A distinctive feature of espresso is the crema, a golden, frothy layer that forms on top due to the emulsification of coffee oils during the brewing process. It adds to the texture and flavor of the espresso.
5. Grind Size: The coffee grounds used for espresso are much finer than those for drip coffee or French press. The correct grind size is essential for a balanced extraction—too coarse, and the espresso will be under-extracted and weak; too fine, and it will be over-extracted and bitter.
6. Espresso Drinks: Espresso serves as the base for many popular coffee drinks, including:
   • Latte: Espresso with steamed milk and a small amount of foam.
   • Cappuccino: Equal parts espresso, steamed milk, and milk foam.
   • Macchiato: Espresso “stained” with a small amount of milk foam.
   • Americano: Espresso diluted with hot water to mimic the strength of regular coffee.
   • Flat White: Similar to a latte, but with a higher ratio of espresso to milk and a thinner layer of foam.
7. Manual vs. Automatic Machines: Espresso machines range from manual, which require skill and precision, to semi-automatic and fully automatic, which make brewing espresso easier and more consistent. There’s also “super-automatic” machines that handle grinding, tamping, and brewing.
8. Short vs. Long Shots: A regular shot of espresso is called a “normale,” but there are also variations:
   • Ristretto: A short shot using less water, resulting in a more concentrated and intense flavor.
   • Lungo: A “long” shot with more water, leading to a more diluted, slightly bitter taste.
9. Cultural Ritual: In Italy, espresso is traditionally enjoyed as a quick drink, often while standing at a café bar. It’s a social and cultural staple, typically consumed multiple times a day.
10. Global Popularity: Espresso is now a global phenomenon, influencing coffee culture worldwide. Specialty coffee shops and chains have popularized espresso-based drinks like lattes and cappuccinos, making them common in everyday coffee consumption.