A gunfire has its origins within the British Army, sometimes made by mixing black appetite control tea with rum, though in Australia and New Zealand it's more often made with black espresso as a substitute. At Starbucks, a double shot of espresso within the espresso could also be termed a "black eye", and a triple shot a "dead eye". Some establishments merely serve an espresso with a sachet of condensed milk for patrons to make themselves. One of these espresso maker is also called vac pot, siphon or syphon coffee maker, and was invented by Loeff of Berlin in the 1830s. These devices have since been used for greater than a century in many parts of the world and extra recently have been given a new use by bartenders and chefs to make hot cocktails and broths. As a time period, it usually means "espresso", whereas in technical discussions, referring to the long drink, it might more narrowly be known as Swiss caffè crema.

Espresso is generally denser than espresso brewed by other strategies, having a better concentration of suspended and dissolved solids