La Marzocco has been producing espresso coffee
machines for use in cafés since 1927.
In February of 1939, when machines being manufactu-
red were exclusively of the vertical boiler type, “La
Marzocco” designed and built the first horizontal boiler
machines, for which it obtained a “patent”.
Second World War brought an end to production of cof-
fee machines, and it prevented the Bambi brothers from
maintaining the patent obtained and therefore, at the
end of the war, all the coffee machine producers began
manufacturing again and they adopted the “horizontal”
boiler, which was more practical and suitable for new
demands and which is still in use now.
Throughout time, various machines have been designed
and built: of the type operating on “Water/Steam” and
on the principle of “Hydrocompression”, and of the lever
operated, air and steam type; semi-automatic and auto-
matic, with mechanical and electrical actuators, up until
current production which consists of machines allowing
continuous “brewing” operation.
CHARACTERISTICS PARTICULAR
TO THE LA MARZOCCO MACHINES
The great majority of the espresso coffee machines being
built today, of almost any brand, are of the “continuous
brewing” type, whose basic concept is to use the same
water in the tubing, directly to brew coffee by increasing
its pressure mechanically and heating it in advance.
In any case, a good cup of coffee is the result of 4 highly
interdependent components, to such extent that if only
one of them is not quite in perfect harmony with the
others, the resulting cup of coffee will turn out not quite
as pleasant in taste.
The 4 basic components are:
1) coffee bean mix;
2) water;
3) coffee grinder;
4) espresso machine.
1) Coffee Mix
Independently of the various qualities of coffee that
make it up, the type of toasting, etc., the freshness of the
coffee beans and the way they are preserved is very
important.
For coffee beans to be used on espresso machines, it’s a
good rule of thumb to wait at least 8-10 days after toa-
sting, so that the beans may re-absorb part of the humi-
dity they lost during the toasting process itself, and to
use coffee beans within 3-4 days of opening their con-
tainer.
2) Water
Within the limits imposed by the type supplied locally,
water should be free of bad savours and “softened”
using a suitable water softener in order to avoid calcium
build-up; in any case, hardness should not exceed 9°F. If
water tastes like chlorine it is recommended that you use
an active carbon filter.
3) Coffee Grinder
It must allow you to grind coffee beans in a wide variety
of granule sizes, in the most uniform manner possible
and, once you have established the amount of ground
coffee required for each cup, the grinder must guarantee
a constant amount from dose to dose. It is best to grind
coffee from time to time, trying not to leave any ground
coffee in the grinder overnight and during days off.
4) Espresso machine
Among other things, the espresso machine must gua-
rantee the following qualities:
A) the most appropriate water temperature for the type
of coffee mix used, constant in time so as to ensure that
a good cup of coffee may be prepared any time, whether
you have to make several, one after the other, or one
from time to time.
B) a constant water pressure through the brewing group
and the coffee mix.
As far as the “B quality” is concerned, it is usually obtai-
ned by means of the same system in all the “continuous
brewing” type machines, that is by using a positive-dis-
placement motor pump, while “quality A” can be obtai-
ned with various systems.
The great majority of manufacturers uses systems which
are very similar to one another. The underlying principle
is to heat up the water used for brewing coffee, which
comes directly from the pipes and is pushed by the
motor pump, by running it through coils or cartridges
(small containers) which are located in the boiler. It fol-
lows that the latter must be quite large, which entails a
noticeable power consumption, and the temperature
may be controlled exclusively through a manostat, a
device which is specifically designed for controlling pres-
sure and not temperature; indeed, the temperature
changes every time the water/steam ratio in the boiler
changes, and even more so when the latter is replenis-
hed with cold water.
It is quite obvious that the coils or cartridges which
supply water to the brewing groups are very sensitive to
the above changes. Furthermore, the heat exchange bet-
ween the main boiler and the coil varies greatly when, as
time goes on, conduction of heat is reduced due to cal-
cium deposits forming on the inside and outside of coils
or cartridges. In light of the above, and to avoid wasta-
ge of electric energy required to keep large quantities of
water at operating temperature/pressure, when only a
small part is utilized, our machines have been designed
with 2 small boilers, of the size which is most suited to
the kind of services they have to offer.
One of them, a “STEAM GENERATOR”, is used to deliver
steam and hot water for various drinks while the other, a
“HOT WATER GENERATOR”, is used for the coffee. The
latter, therefore, produces hot water used exclusively for
brewing coffee, which will flow out, every time the spe-
cific group is activated, thanks to the force of the cold
water (actually produced by the positive-displacement
pump). The temperature of such water is controlled by a
THERMOSTAT-like device which is extremely sensitive
and has a differential of ±1° C, adjustable to 1/10 of a
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English
8. History and use of the “La Marzocco” Coffee Machines
