Detail knowledge about coffee grinding tools gathering
Updated: Aug 5, 2019
Before making coffee, we need to use a grinder to smash the beans and then brew them. How do you distinguish the different coffee grinding tools on the market?
When making coffee, whether it is espresso or hand brewing, after preparing the relevant equipment tools and hot water, the most important thing to do is to grind.
Although coffee powder is called "powder", in fact, coffee powder is small coffee granule. Process should be more appropriate to be called "crushing", but we usually call it "grinding beans".
Coffee mills are divided into manual and electric grinding according to power source.
In terms of the shape of the grinding disc, We divided them into flat burr and conical burr, blade cutter, ghost burr, round burr etc.
First let's talk about flat burr.
The main working principle of the flat burr is to drive the grinding disc by the motor, use the centrifugal force to pull out the coffee beans, and then use the various tooth patterns on the cutter disc to smash the coffee beans.
Flat knife grinding is to crush the beans by cutting. Generally speaking, flat burr grinding is the main means of crushing with less extrusion.
The flat burr teeth are finer, the cut surface is sharp, the uniformity is good, the price is cheap, and it meets the requirements of general household production, but the disadvantage is that compared with other grinding burr, flat burr will bring out the more obvious fine powder and flakes. And this cutting disc is less efficient. The sharp-angled structure of the ivory is easy to accumulate powder. The efficiency of washing the bean bin is poor, causing more coffee beans wasted. Maintenance frequency higher.
Some patented coffee disc is designed with partial extrusion function, such as the most popular and cost-effective rounded disc.
Compared with the flat burr, the round burr has a large gap between the teeth, and the cross section of the tooth has a conical shape. Because of its extrusion function, the efficiency is higher than that of the flat burr, and the flake and the ultrafine powder are greatly decreased. This kind of grinding burr is of good quality and low price. The price is not expensive and the diameter of the cutter disc is basically uniform. Very convenient, relatively sharp angle structure, the washing bean will be more efficient, and the tooth prints are not as easy to accumulate powder as the flat burr.
We believe that at the same speed, the efficiency of round burr is much higher than flat burr.
Ghost teeth are special. If the same kind of beans are often used to make hand-washed coffee with ordinary flat burr and ghost burr. We can taste that the coffee flavor of the ghost tooth is more complicated and colourful.
The structure of the ghost tooth is different. I think it's the reason is that the flavor is complicated. It combine extrusion and slicing process at the same time although principle is not as that simple.
Microscopic observation revealed that the flat burr grinded particles is a hexagonal shape, the cone shaped disc grinded particle is a sheet-like strip. and the ghost teeth exhibited a multi-faceted shape. The round blade presents a similar shape to ghost tooth.
Let's talk about the conical coffee miller then. The cone shaped disc miller looks like this (see photo).
The main pulverizing mechanism of the conical miller is to use gravity to make the beans fall into the burr disc, then to crush the beans. Some electric grinders and almost all manual grinders use conical grinding burr. The main material of grinding disc may be stainless steel, tungsten steel and other materials. The general manual grinding cone shaped grinder use ceramic material, and the some advanced hand grinder will use stainless steel, tungsten steel and other materials for the grinding disc. The ceramic material is not like the ceramic knife we know made of cubic zirconia. Ceramic conical coffee grinder disc material is more like a stone-like material. So it will wear out in the future, which will affect the uniformity of coffee powder.
The mechanism of the ceramic cutter disc basically is crushing on the coffee beans. The gravity is used to draw the beans into the coffee cutter disc to crush coffee into smaller particles. And there is almost no cutting process. The metal manual grinding part has bit cutting effect, but The main mechanism is still crushing. The electric cone grinding machine hardly adopts the ceramic grinding disc. The ceramic is brittle, and the electric motor has a large torque. If the beans are hard or have impurities, the cutter disc is easily damaged.
Manual grinding often produces uneven powder. The main reason is that the central axis is unstable, the fineness regulator is unstable, and the direction of the force source is unstable. Above can easily cause Displacement of the central axis.
These are the natural defects of hand grinding. It is necessary to strengthen the coaxial stability of the central axis and strengthen the stability of the fineness regulator. As a result, the price will be very high.
By the way: The electric conical coffee grinder cost below $500 is much btter than the same price hand grinding. The speed of hand grinding is far less than that of electric grinding.
Do not ever think that hand grinding is an inexpensive starting grinder as the alternative of electrical coffee grinder. But the hand-grinder portability is good (small size), the power source is easy (man powered).
Manual coffee grinder can only be seen as a backup for the electric coffee grinder. If Electrical miller is broken, it can be a temporary substitute, or as The decorations in the store.