What's the difference between a coffee grinder and a flat knife? which kind of coffee grinder?

What's the difference between a coffee grinder and a flat knife? which kind of coffee grinder?

Italian bean grinder

The Italian bean grinder is divided into a cone knife and a flat knife.

The cone knife type bean grinder is longitudinal grinding from top to bottom, with a long path, and its advantage is that it can use lower rotational speed to achieve a better grinding effect, and produces less heat energy, can retain more aroma of coffee powder, and the demon's thickness is more uniform, so that the flavor is clearer, but the price is also much more expensive.

The flat knife type bean grinder is ground in a horizontal way, and the grinding path is shorter and the speed is higher. High-speed grinding will produce more heat energy and fine powder, which has a great influence on the flavor of coffee powder.

Therefore, the size of the cutter head of the high-end Italian coffee machine is also larger, and it can grind more coffee beans at one time, so as to increase the grinding efficiency and avoid the opportunity of producing heat energy at high speed.

First, let's talk about uniformity. I'm sorry to tell you that there is no absolute uniformity under the microscope! The powder produced by the three types of knives is uneven! So there is no such thing as an absolutely uniform bean grinder. The uniformity of your eyes is fundamentally different from the actual uniformity!

Second, the structure of the powdered particles is completely different after grinding, such as conical knife, ghost tooth and flat knife. Through grinding, it can be observed that the powder structure and shape of different knife shapes are completely different.

Third, the effect of powder structure on the flavor of coffee. This is just the extraction process. The core of the extraction process is the higher extraction rate at the high water temperature and the higher extraction rate at the fine point of grinding. So what is the effect of powder structure on extraction? It's nothing but a water block! Cone knife powder under the microscope, the main body of the powder structure will have many protruding outer fulcrum, just like a hedgehog. After a lot of powder particles gather, it is impossible to match them completely because of the external fulcrum. The gap will be larger and the flow of water will pass faster. The flow of water passes faster, so the extraction is relatively low. Ghost tooth powder, ghost tooth grinding out of the powder waist slender, relatively smooth, the coupling between powder and powder will be better. The gap is also small, the flow of water through will be relatively slow, and the extraction will be relatively more. From the taste, the same beans, the same amount of powder, the same water temperature, the same fineness of powder, ghost teeth will have better sweetness. Flat knife grinding powder, than conical knife protruding fulcrum is less, particles into blocks, waist than ghost teeth to be stout. Personally, I think the water resistance of flat knife powder should be the greatest! Ghost tooth powder waist is too thin, peace knife powder compared to the resistance must be less. Then the powder ground by the flat knife, from the structural point of view, the convex fulcrum of the powder particles is less, so the coupling is much better than the cone knife powder. The gap is tighter than the cone knife, the water resistance is also larger, and the extraction is also a little more.