Espresso or caff? espresso is a concentrated coffee beverage brewed by forcing very hot, but not boiling, water under high pressure through coffee that has been ground to a consistency between extremely fine and powder.
The defining characteristics of espresso include a thicker consistency than drip coffee, a higher amount of dissolved solids than drip coffee per relative volume, and a serving size that is usually measured in shots, which is about 30ml (1 ounce) in size. Espresso is chemically complex and volatile, with many of its chemical components quickly degrading from oxidation or loss of temperature. Properly brewed espresso has three major parts: the heart, body, and the most distinguishing factor, the presence of crema, a reddish-brown foam that floats on the surface of the espresso.
