The term café-espress has been used since the 1880s, well
before espresso machines existed. It means coffee made to order, expressly
for the person ordering it. It also means coffee fresh in every sense of
- Made from fresh beans roasted at most two weeks prior to use,
- Ground just before brewing,
- Brewed just before drinking.
Ideally, all cafés and restaurants would serve even their
regularly brewed coffee as espresso in this larger sense—freshly
ground in press pots, neopolitans, vacuum brewers or table top
pourovers. The aroma of good coffee is delicate and dissipates in a
matter of minutes after grinding, whether it is brewed or not.
Early steam-powered Bezzera
People are in a hurry. For many workers, waiting five minutes for
coffee to brew is too long. They were also in a hurry 100 years ago when
inventors started looking for faster ways to brew coffee to order. It
being the age of steam, the first attempts used steam rather than water.
A steam brewing contraption at the 1896 World's Fair is said to have
made 3000 cups per hour. Unfortunately, steam-brewed coffee tastes awful
since coffee generally needs to brew at just below boiling
(195-205°F or 90-96°C) to taste its best. In 1901, the Italian
inventor Luigi Bezzera came up with a workable solution. Pavoni
manufactured these first espresso machines in 1905.
This machine was also steam powered. However, the steam does not come
into contact with the coffee. Instead, steam pressure at the top of the
boiler forces water at the bottom of the boiler through ground coffee.
The coffee is held in a group consisting of a portafilter,
a metal filter basket and removable brass mount, and a brew head
into which the portafilter attaches. The piping and group were designed
to act as heat radiators, so the temperature of the pressurized water
dropped from 250°F (120°C) in the boiler to the correct brewing
temperature at the grouphead. This brewing principle is still used in
stovetop mochapots. Since the water was pressurized, the coffee could be
ground finer than in a regular pourover brewer, reducing the minimum
brewing cycle from about 4 minutes to 30 seconds. Espresso machines and
their accompanying coffee grinders became the standard equipment for
making coffee in Italy, Southern France, Spain and Latin America. In
other parts of the world, it followed Italian immigrants who popularized
it in each country they settled.
But technology moves on, and this method is no longer regarded as
specifically espresso, although mochapots and other steam pressured
brewers continue to be marketed under the name. In the 1920s through the
1940s, Italian engineers experimented with pumping devices to increase
the brewing pressure. The first practical one was developed by Cremonesi
in 1938 and manufactured by Achille Gaggia in 1946. It used a hand
powered piston. On machines of this type, steam pressure in the boiler
forces the water into a cylinder, but then it is pressurized further by
a spring-powered piston to about 8 to 9 bar (120 to 135 PSI), or 8 to 9
times the pressure that had been developed by the steam machines. The
spring that powers the piston is compressed by a lever forced down by
the barista (Italian for barkeep)—the person making
the coffee. As with the older generation machines, these lever groups
are designed to cool the water from boiler to brewing temperature.
Early Gaggia lever machine
Now we have modern espresso in the restricted sense of the
term—coffee brewed with water at 8 to 9 bar pressure between
90°C to 96°C. This technology also explains why modern espresso
uses the same amount in a small one ounce drink as was previously used
in 2½ ounce demitasse espressos or five ounce regular cups of
coffee. The pressurization cylinder could only hold that much water,
otherwise the arm strength required to compress the spring would have
been prohibitive. Finally, if it's done just right, the added brewing
pressure creates a nice layer of foam over the coffee called crema.
What's this scum on my coffee?!?
Legend has it that the first patrons to drink the new potion at
Gaggia's coffee bar didn't think it was so nice. They asked, "What's
this scum (sciuma - foam) on my coffee?" So in a marketing ploy, Gaggia
called the new drink "caffè crema" instead of espresso. For about
a decade, espresso machines were made with some groups using the old
style one bar steam pressure and others using the new-fangled nine bar
spring-lever pressure. But in time, the new style won out and became the
true espresso. The term "caffè crema" died out, only to be
revived for another style of coffee drink by the Swiss in the 80s.
The next innovations were commercialized in 1961 by Faema. Instead of
a piston situated between the boiler and ground coffee, they used an
electric pump to move cold water through a heat exchanger that traversed
the boiler to the grouphead. The heat exchanger was designed to heat the
water to the correct brewing temperature. Since the group was no longer
used to cool the water, it too had to be held at the correct brewing
temperature. Faema used a hot water circulation system to keep the group
hot; other manufacturers used a hot water jacket or kept the group in
close thermal contact with the boiler for the same purpose.
The cylinder on lever groups only held an ounce of water, limiting
the volume that could be used to prepare an espresso. There are no such
limits for an electric pump. So why hasn't espresso gone back to being a
regular or demitasse cup of coffee, only brewed more quickly using
pressure? This is precisely what the Swiss do for the drink now called a
café crema. However, by the time the newer electric
pump models came out, espresso had become its own drink category, and
people had developed a taste for the "little cup." The only change to
espresso created by electric pump machines is the introduction of the
double espresso—double the water and double the coffee for a drink
with the identical concentration and taste.
Home lever machines had been designed since the 1960s, but they
didn't achieve a mass market because of two severe shortcomings: the
groups were too small, so the coffee would overheat after a few shots,
and the shortened levers required considerable arm strength. The next
big breakthrough came in the late 1970s. A company called Ulka
introduced a small, inexpensive pump that could still produce the
pressure required by modern espresso. This made affordable and small
home pump espresso machines a practical possibility. Gaggia and Quick
Mill brought out the first models and many other manufacturers soon
Next page: Today's espresso scene...