Blog Categories

Blog Categories

Pump pressure

Each blend of coffee is the result of the selection of coffee varieties and processing techniques: nevertheless, even if the best raw materials have been chosen and the techniques used are the most sophisticated, for a perfect extraction of the coffee in the cup is important that the machine and the grinder are properly adjusted, and that the bartender uses them correctly.

9 bar

The pressure due to enhance the creaminess and correct extraction, together with the water temperature. On average we use a coffee pressure of 9 atmospheres that can vary according to the tastes that you want to enhance from the same mixture, such as the degree of acidity, bitterness, sweetness. With a calibration that is too low the coffee would be under-extracted, on the contrary with a higher pressure the same would be over-extracted.

The correct operating parameters of the espresso machine, although varying according to the make and model of the machine used, can be summarized as follows:

Boiler pressure: 0.95 bar ± 0.05

Pump pressure: 9 Bar ± 0.5

Temperature: 90 ° C ± 2

Extraction time: 25 sec ± 2

Dose grams: 7 g

Volume in cup: 25 ml ± 2 (in 25 sec.)

Cream height: 2-3 mm

Pressure of the pump: the pressure gauge lever, during coffee extraction, must be in the green zone, between 8 and 10 bar (correct pressure 9 bar). As the pump pressure increases, delivery speed increases, and time of coffee extraction.

Boiler pressure: it can vary between 0.9 and 1.1 bar; between 0.9 and 1.0 for machines that use relatively few coffees during use, between 1.0 and 1.1 in the case of machines that work a lot (more than 50 coffee / hour) and use boiler water for cappuccinos and tea. The boiler pressure is directly proportional to the temperature reached.