The correct pronunciation of “espresso” is an age-old argument that coffee enthusiasts have been having for years! But as it turns out, those who call it an “expresso” aren’t completely wrong.

The Italian term espresso means “expressed” or “pressed out”. This is because espressos are made by forcing very hot water under high pressure through finely-ground coffee beans. So, while the correct pronunciation is ES-presso, you can see where people are coming from.

Because of the similarity of espresso to the English word express—and the promise of coffee being prepared with relative swiftness in contrast to percolating devices, it naturally caught on for espresso to be interpreted as expresso—reflecting the “express” nature of delivery—and consequently spelt as such. Espresso machines operated faster than percolators, delivering the coffee to the customer at a speed requiring less of a wait.

By the middle of the twentieth century, around the time a café owner named Achille Gaggia patented the first modern espresso machine for commercial use (and the first that produced the crema that we associate with espresso today), the term espresso made its way into English.

Source: Merriam Webster, Esquires Coffee