Why do we grind coffee?
The aromatic substances developed in the roasting (Specifically with the Maillard reaction ) remain trapped in the structure of the grain and only by grinding it can we free them and bring them inside our cup of coffee .
The grinder it is the tool that allows us to transform the grains into powder at the required moment coffee , increasing the contact surface with the hot water.
How a Grinder is made
THE coffee grinder with dispenser (even if now surpassed by On Demand) are composed of a Hopper or Bell, the Millstones and the Dosator. The coffee beans are poured into the Hopper, this conveys the beans towards the pair of grinders. The grinders that are made of tempered steel can be flat or conical in shape and by rotating at high speed they crush the grains that end up in the dispenser which in its lower part has a star divided into compartments of equal size and at each click of the lever dispense the desired quantity. (To work properly the dispenser must be filled to cover all parts of its star.)
Everything is fine grinder has the ability to adjust the size of the compartments of the star to increase or decrease the dose delivered in the filter (grammage).
Obviously we do not recommend doses lower than 7/8 g of coffee .
How to adjust the grind
The grinding must be adjusted according to the type of grain fiber and the ambient humidity. Under the hopper there is a threaded ring nut with impressed numbers (or there are two verses, FINE AND COARSE). Moving it towards the larger number increases the distance between the pair of millstones, vice versa it decreases.
How to understand if we have set a correct grinding (grain size)
A correct granulometry allows the extraction of the espresso in 25/30 seconds. If the coffee powder is too coarse, the water flow will drop quickly and the espresso will be Under-extracted. Body and aroma will be very low. Conversely, if the powder is too fine, the coffee will drip slowly obtaining an Over-extracted coffee. In this case, the water will extract unwanted substances and our espresso will have bitter notes and sensations of astringency.
