PREPARATION

With tea, coffee is the drink solder in the world. The preparation methods can be classed in two principal systems.

1)By infusion: when the ground coffee is let steep in the boiling water, as for Turkish coffee.

2)By percolating: when the heated water is let pass throughout the ground coffee as for espresso coffee, for mocha and Neapolitan coffee.

Between these, the espresso coffee is the one that uses at the top the 700 substances which represent the volatile aromas: in fact, thanks to the pressure exerted, it is possible to extract part of the oils and the colloids responsible of the bigger excitement of our gustative senses.
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THE BLEND
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THE COFFEE GRINDER

Its perfect working and the exact grinding of the coffee are fundamental for the success of espresso coffee. Its aim is to transform the coffee beans into powder in order to offer to the water a bigger contact surface, which lets a bigger extraction. If you change the fineness degree of the ground coffee you will change the resistance to the water passage growing or reducing the extraction degree. The coffee grinder is composed by: the bell, the measuring device, the wheels (flat or conic), the little press. The replacement of the wheels in a coffee grinder with level wheels has to be made after about 600 kg of coffee, and in a coffee grinder with conic wheels after about 1,200 kg (the motor revolutions are lower). The main defect of the coffee grinder is due to the cleaning of its parts, as coffee contains some oils that, with the prolonged use, make the product rancid ruining in this way the fresh coffee that is inserted in the bell.

Maintenance of the coffee grinder:

Daily: elimination from the measuring device of the old residual ground coffee, adjustment of the grinding based on the air dampness controlling that espresso coffee is obtained in 25 - 28 seconds, control of the dose that has to be 7 grams for every coffee.

Monthly: control of the wear conditions of the wheels and complete control of the coffee grinder.

THE ESPRESSO MACHINE

It must always be in perfect conditions to have a good espresso coffee: for this reason we advise to keep it always alight even during the night, in order to have a machine in pressure and at the right temperature.
Even if this system is not energy saving, it allows to avoid expensive tests due to on one hand to the limestone accumulation in the boiler, and on the other hand to the metal dilatation and of the other machine components that would be worn out by continuous activation and deactivation of the machine. The parts to constantly control are:

• Indicator of the water level in the boiler (intermediate value in the scale).
• Indicator of the water temperature in the boiler (value between 90-100°C).
• Manometer for measuring the pressure in the boiler (value between 0.9-1.2 atm.).
• Manometer for measuring the pressure of the volumeter pump (value between 8-10 atm.).
• Cleaner. It is composed by resin filters which maintain the hardness degree of the water within 9°F. These filters must be regularly regenerated with coarse salt, until the replacement of the resins (about once a year). An excess of calcium and magnesium make the coffee bitter and avoid the production of the cream.

  Maintenance of the espresso machine:

  Daily: Control of these components: water with constant pressure, manometer of the water pump, manometer of the pressure in the boiler, temperature and level of the water in the boiler, evening cleaning of the filter, the filter holder, the pipes and the seals.