Many believe that the larger the size of the beans, the better the quality of the coffee.
Very often the large coffee beans give the impression of high quality to the blend. But is it really true, that the size of the beans influences the quality?
Experts point out that often the larger coffee beans are those of high altitudes, generally above 1000 meters above sea level. These are high-profile coffees in terms of aromatic complexity, above all thanks to the thermal excursions to which they are subjected. However, this correlation brings along numerous exceptions.
Certainly the size of green beans stays fundamental in the selection and processing of coffee, especially in order to have a uniformed roasting quality. Through time also so-called sieves have become more and more popular. This method is not too scientific, but very effective for classifying the size of coffee beans.
This technique requires that the coffee beans are poured on a series of sieves, which consist of holes of increasingly smaller diameter. The sieve on which the various grains will stop, being at that point larger than the holes, will determine their sieve measure.
Technically speaking, the size of the sieve holes is shown as: 17/18, 15/16, 13/14 and so on. The sieve holes are measured in inches and the standard size of one inch is of rounded 64.
Brazilian coffee, the most highly production in the world, is classified with the “New York” 17/18, 15/16, etc. system. These systems vary depending on the producing countries.
In Africa, for example, classifications such as AA, AB, etc. are used. In this case AA is a coffee classification term that refers to a dimension above the sieve size 16.
Other famous coffees, such as the Supremo and the Altura for example, follow even different methods, some of them found in the table here above.