Coffee grindability parameter adjustment course hand-brewed coffee and Italian concentrated grinding thickness reference

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Grinding is very important for coffee extraction, it can be said that the thickness of coffee grinding directly affects the flavor of a cup of coffee. According to different extraction methods, the grinding degree of coffee also needs to be changed. The fineness of coffee grinding will directly affect the extraction time and the extraction rate. The finer the coffee is ground, the denser the powder layer is, there are more coffee powder particles in contact with hot water, the extraction resistance increases, the easier it is to prolong the extraction time, and improve the extraction rate, it is easy to over-extraction. On the contrary, the coarser the coffee is ground, the larger the gap between the powder layer is, the less coffee powder particles are in contact with hot water, the smaller the extraction resistance is, the less easy it is to prolong the extraction time and reduce the extraction rate, which is prone to insufficient extraction. As soon as the coffee beans are ground too fine and the water touches the surface of the coffee powder too much, too many unnecessary impurities will be extracted, even the bitterness will come out; but if the coffee is ground too coarsely, the delicacy is still hidden deep inside, where the hot water is out of contact. the brewed coffee does not have enough aroma.

When extracting espresso, we must make efforts to fill the coffee powder to make it resistant to high-pressure hot water in order to really extract the essence of coffee. Therefore, it is more sensitive to the degree of grinding, the more uniform grinding, the more compact the coffee powder, and less space, can produce balanced resistance to water, so that a cup of Espresso can be extracted successfully. For example, the coffee grinder used in Qianjie is Pegasus 900N, with 8 large scales on the cutter head scale and 10 small scales between the large scales. In the daily production, after the grinding machine is adjusted to zero, the sunflower sunflower with Qianjie coffee is produced at about 2 degrees Celsius. Take one-day debugging as an example, it takes 32 seconds for 20 grams of powder to extract 40 grams of coffee liquid using a 2-scale grinding degree, then it takes 29 seconds to adjust the 2 scale to 1.9 minutes and 20 grams of powder to extract 40 grams of coffee liquid. The thickness of the 2 and 1.9 scales cannot be recognized by the naked eye, but the effect of extraction on an Italian coffee machine is very obvious.

And the degree of roasting of coffee beans will also be adjusted, the deep-roasted coffee beans should be properly adjusted, and the shallow-roasted coffee beans should be adjusted fine. The shallower the roasting degree of coffee, the more complete the fiber, the hard beans, not easy to extract, can be slightly adjusted to grind, but not too fine, so as not to highlight the sharp sour taste. The deeper the roasting degree of coffee fiber is damaged, the easier it is to extract, so choose a thicker grinding. Too fine can lead to bitterness. When cooking with different utensils, the thickness of the grinding degree is also different. For example, the degree of grinding from fine to coarse is the Turkish pot, Italian coffee maker, mocha pot, hand punch, siphon, French pressure pot. The degree of grinding of Turkish pot and Italian coffee machine is the finest, roughly showing flour powder (200 microns), while the grinding degree of hand punching and siphon will be slightly thicker, with the feeling of sand (about 600 microns), and the grinding of law pressing pot is thicker (850 microns). 1: Turkish powder: if the grinder can reach, this is the finest coffee powder 2: fine espresso powder: very fine coffee powder, caking is possible 3: espresso powder: fine coffee powder, caking is possible Commonly used in the production of espresso 4: fine filter powder: between espresso powder and filter powder 5: filter powder: coffee powder has the texture of super cotton sugar for seasoning, which is very different from the third grade fine powder. 6: coarse filter powder: accuracy is similar to granulated sugar 7: coarse powder: suitable for immersion brewing, such as French kettle. Accuracy is similar to sea salt detritus 8: very coarse powder: similar in size to rock salt, only suitable for long-term immersion cooking

According to the European Fine Coffee Association, the grinding thickness of the French kettle indicates that each coffee bean is ground into 100-300 particles with a diameter of about 0.7 mm. The electric trickling filter is medium ground, and each bean is ground into 500-800 mm, with a diameter of about 0.5 mm. Moderate grinding by hand and siphon each bean is ground into 1000-3000 particles with a diameter of about 0.35mm. The fine grinding of espresso in which each bean is ground into 3500 particles with a diameter of about 0.05mm. Turkish coffee pots are ground into flour, about 15000-35000 particles each. For the degree of grinding, it may be more elusive. You only need to remember the simplest point: if you want to achieve the same extraction rate, the finer the grinding, the shorter the cooking time; the rougher the grinding, the longer the cooking time. The esoteric point is that this is the same as the principles of physics, increase the surface area and contact area, then the hot water will be more fully exposed, of course, the faster it will be boiled.

As for the need to get this coffee bean grinding degree to which scale. Qianjie believes that the hardness of each kind of coffee beans is different, and the parameters of each grinder will have deviation, so it is not rigorous to talk about the scale under the premise of this uncertain factor. So how to set your own degree of grinding? In fact, this is also very simple, for example, after buying a bean grinder, there will be instructions for use, or you can ask the merchant. Will get a grinding suggestion. Note that this is a suggestion rather than a certainty, we can start with this suggestion to find a suitable degree of grinding. On the other hand, remember to use the same grinding scale for coffee, knowing that the density and roasting degree of each bean is different. The beans currently on the shelves in Qianjie will be adjusted through a standard sieve to achieve the best state of production. After the purchase of the grinder is not once and for all, but also diligent maintenance, regularly remove the cutter head, remove the grease inside, the cutter head is consumable and should be replaced regularly. Otherwise, the ground coffee particles are uneven, affecting the coffee flavor.

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