History and culture
The development of the espresso machine
What the documents CoffeeHQ has opened say about how the espresso machine came about: a 1902 patent for a machine that made each cup separately, and a maker's own account of the move from steam to pressure between 1938 and 1948. What is only reported, and not read, is marked.
Each section below is labelled by how well-established its claims are — look for the label under each heading.
What 'espresso' meant before pressure
CoffeeHQ synthesis · early 20th century · Italy
The machines of the early twentieth century were boilers. Water was heated in a closed vessel, and steam and hot water from it were sent through a small quantity of ground coffee held under a tap on the outside. Their point was speed and freshness for a busy bar rather than pressure in the modern sense. The patent described below states the aim directly: the coffee for one cup is prepared separately, so that what is served is always fresh. That idea, one portion made to order in front of the customer, is the part of espresso that predates everything else about it.
Sources: Coffee-making machine (United States patent 726,793)
An earlier patent that is reported, not read
Widely repeated legend — not established fact · 1884 · Italy
Accounts of the machine's history usually begin in Turin in 1884, with a patent granted to Angelo Moriondo for a steam machine intended to make coffee quickly for a bar. CoffeeHQ has not opened that patent or the Italian patent bulletin in which it is said to be recorded; the claim reaches this page only through general histories. It is repeated here as a reported starting point, without the details those histories attach to it.
Sources: Encyclopaedia Britannica coffee and coffeehouse history entries; The World Atlas of Coffee
The 1902 patent: one cup at a time
Documented history · 1902–1903 · Italy; United States
The earliest document CoffeeHQ has read is United States patent 726,793, 'Coffee-making machine'. It was filed on 10 June 1902 by Luigi Bezzera of Milan and granted on 28 April 1903, and it names Desiderio Pavoni of Milan as assignee. Its five claims describe a boiler with a heating chamber in its lower part, a delivery cock near the bottom with a bell-shaped outlet, a receptacle for the coffee beneath it, and a perforated plate between the two to spread the water and steam across the coffee. The passages for water, for steam and for letting excess steam escape are all worked from the one cock. Two things follow from the document itself. The machine made coffee by the cup, and the rights to it were assigned to Pavoni, whose name the commercial machines carried. What the patent cannot show is how many were built or how the coffee tasted, and it states no pressure.
Sources: Coffee-making machine (United States patent 726,793)
From steam to pressure: the maker's account
Popular commercial narrative · 1938–1948 · Italy
The change that produced espresso as it is now understood is usually credited to Achille Gaggia, and here the source is the company that bears his name. By its account he filed patent number 365726 on 5 September 1938 for a mechanism that used the pressure of hot water instead of steam, and which gave the coffee a layer the company calls crema naturale. Under 1947 the company records a second patent, for a mechanism in which a lever drives a piston. Under 1948, again by its account, he founded a company with the entrepreneur Carlo Ernesto Valente and produced his first machine, the Tipo Classica. This is a company telling its own history, and the patents were not opened; it is evidence of what the maker claims and of the dates it gives, not an independent finding that nothing similar existed before.
Sources: Gaggia history
What this page does not establish
CoffeeHQ synthesis
It gives no pressure for any historical machine, because neither document read states one as a specification. It does not describe the electric-pump machines of the 1960s, the heat exchanger, or the later history of home machines: none of those has a document behind it here. And it does not settle who 'invented' espresso. The record read supports a narrower statement: a 1902 patent for making coffee one cup at a time, and a maker's dated claim to have replaced steam with water pressure in 1938, patented a lever and piston in 1947 and built a machine in 1948. How the machine works today is covered on the espresso machine pages.
Sources: Coffee-making machine (United States patent 726,793); Gaggia history
Related
Preparation traditions
How this history is practised today, in CoffeeHQ's international preparation atlas.