The grinding, or particle size of the coffee is a fundamental element in the preparation of a perfect cup of coffee. Many coffee enthusiasts consider this process a real ritual, in which art mixes with science; in fact, correct grinding can make the difference between a mediocre espresso and a drink with an exceptional taste.
In this article we will explore the importance of coffee grinding, the different types of grinding and how to obtain the best results for an unforgettable tasting. The grain size directly affects the quality and flavour of the final drink, as it determines the extraction of essential oils and soluble compounds present in the coffee beans.
The grinding of the coffee is important because increases the surface of the coffee in contact with the water, facilitating the extraction of the aromatic substances and allowing you to create a balanced cup of coffee. The freshly ground of the coffee is also important to obtain a more creamy and full-bodied drink: it must be adjusted according to the method of preparation of the coffee, the type of coffee beans and roast level.
How is coffee ground?
The coffee grinder is a very important piece of equipment in the bar, often even more important than the espresso machine, which uses a pair of grinders (conical or flat) allows you to grind the coffee beans into small particles.
Adjusting the coffee grind increases or decreases the distance between the grinds: bringing them closer together you get a finer grain size, moving them apart will result in larger grain size.
Each grinder has its own system for regulating the distance of the burrs manually or electronically, usually numbers or circles of various sizes are indicated to facilitate the setting of the grind.
How to adjust the coffee grind?
To adjust the coffee grind, it is necessary to choose the type of grind based on the preparation method, adjust the coffee grinder according to the desired grind, adjust the grind based on extraction time and extraction method, and experiment with different grinds to find the perfect one for your personal taste.
Coffee grinding and the main types of extraction
The grinding of the coffee is an important factor in obtaining a quality drink. Here is the ideal grind based on the main types of coffee extraction:
- Espresso: fine grinding to obtain a creamy and full-bodied drink.
- Moka: the ideal grind is medium-fine.
- French Press, Aeropress: the grind must be coarse to prevent the coffee from being too bitter.
- V60, Chemex: the grind must be medium-fine.
If the grind is incorrect?
Overextraction and underextraction are two problems that can occur during coffee extraction due to inadequate grinding.
overextraction occurs when the coffee is extracted for more than 25-27 seconds and when the particle size is too fine. The result in the cup is definitely a bitter and astringent drink. To regulate overextraction it is necessary to make changes to the coffee grind in order to make it coarser to reduce extraction times.
underextraction occurs when all the aromatic potential is not extracted from the coffee: it occurs when the grinding is too coarse and the result is a coffee with little body and no of positive aromas. To remedy the underextraction it is necessary to adjust the coffee grinding, make it finer and increase the extraction time.
Another crucial aspect is the freshness of the product. Ground coffee begins to lose its aroma and flavor rapidly due to oxidation. To obtain a perfect cup it is advisable to grind the coffee at the moment. In this way we do not lose aroma and taste.