What is the correct grind size for espresso?

The correct grind size for espresso is indeed a fine grind that resembles table salt. This specific grind is crucial for the espresso brewing process, as it allows for optimal extraction during the short brewing time typical of espresso machines. The fine particles create a large surface area for water to interact with the coffee, facilitating a quick extraction of flavors, aromas, and oils.

A coarse grind would result in under-extraction, leading to a weak and watery shot, while a medium grind may not extract sufficiently fast enough for espresso, resulting in a sour taste. An extra fine grind, although it might seem logical for creating a stronger brew, can lead to over-extraction, making the espresso bitter and harsh. Thus, the fine grind that resembles table salt strikes the right balance for producing a rich and well-balanced espresso shot.