Practical information | are you still obsessed with the grindness of all kinds of coffee? Don't you look!

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Making good coffee is much easier than baking good beans, because the variables of making coffee are relatively simple and easy to grasp, unlike baking, which often receives about water content, hardness, climate, firepower, exhaust valve and exhaust pipe patency.

You only need to remember the simplest point: 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.

Grinding accuracy classification, it has been mentioned before that the different effects of grinding thickness on extraction. Fine coffee powder can accelerate the extraction speed, while coarse coffee powder can reduce the extraction speed. Let's take a look at the precision classification from fine to coarse:

Turkish powder < fine espresso powder < espresso powder < fine filter powder < filter powder < coarse filter powder < coarse powder < very coarse powder < coffee block

The importance of uniform grinding

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 brewing espresso, you must make great efforts to fill the coffee powder to make it resistant to high-pressure hot water before you can really extract the essence of the 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.

Coffee beans become powdered after grinding, and the distribution of powder size has a lot to do with the quality of coffee drinks. The more the size of the powder is concentrated within the target range, the better the flavor will be. If there are too many coarse grains, you will not be able to boil the good taste hidden inside the coffee; if there are too many fine grains, you will make coffee that tastes too miscellaneous and bitter.

Coffee powder with different grinding degrees

Here we use the way of picture comparison to show you several different degrees of coffee powder so that you can have a general concept at the beginning, of course, there may be more and more detailed distinctions in practice, but you can still get a basic visual distinction of the degree of coffee grinding from the picture below, and then you can have more confidence in yourself-- whether you're doing it or talking about it.

Judgment of coffee bean grinding degree 1: ultra-coarse grinding

Often used in iced coffee

Judgment of coffee bean grinding degree II: rough grinding

It is commonly used in coffee made by French Press Pot.

Judgment of coffee bean grinding degree 3: medium and rough grinding

For example, coffee made with Eva Solo coffee maker and hand brewer Chemex Brewer.

Judgment of coffee bean grinding degree IV: medium grinding

Coffee made from a trickle pot Drip Pots is commonly used.

Judgment of coffee bean grinding degree 5: medium and fine grinding

Coffee made by Pots, Siphon Brewers and Pourover Cones.

Judgment of coffee bean grinding degree VI: fine grinding

Coffee made by Espresso coffee maker and mocha pot Moka Pot.

Judgment of grinding degree of coffee beans 7: ultra-fine grinding

Effect of Powder structure on extraction

Flat knife grinding flake particles will be closer to the oblate rectangle, while cone knife grinding block is close to hexagonal, ghost tooth grinding powder waist slender, relatively smooth, the coupling between powder and powder will be better.

Flat knife grinding powder, than conical knife protruding fulcrum is less, particles into blocks, waist than ghost teeth to be stout. A person thinks that the water resistance of flat knife powder should be the greatest!

Cone knife powder under the microscope, the main body of the powder structure will have many protruding outer fulcrum, just like a hedgehog. After many powder particles gather, it is impossible for the powder particles to match 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. 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.

Summary

From the grinding point of view, is the more uniform, the less fine powder is better? This is not the case. As mentioned just now, each kind of knife head has its own advantages and disadvantages. If it is absolutely uniform and there is no fine powder at all, the taste of coffee will be very mediocre, lack of taste and hierarchy, and it is very easy to extract too much. If too much non-uniform fine powder will produce too much miscellaneous smell and affect the smoothness of the extraction, the taste and smoothness will also be greatly reduced.

If you want to know which one is most suitable for your needs, you can only know it when you buy every bean grinder. That's why many players and contestants buy so many bean grinders to make their own comparison. There are also experienced baristas who control the coffee flavor by adjusting the brewing time, technique, and grinding degree, which still won't make the coffee perfect. So even world-class baristas are constantly pursuing high-end equipment and constantly improving their methods.

When you need to get a high concentration of coffee in a short time, the flat knife grinder is a good choice, and the high concentration will also make the aroma rich, so the aroma of using a flat knife will be much more obvious than that of a cone knife.

When better taste is needed, the granular coffee powder produced by the cone knife grinder can reduce the xylem contact time, although the aroma is not as obvious as the flat knife, but even if the extraction time is prolonged, the taste is still better.

When the overall taste is three-dimensional and full, choose the ghost tooth bean grinder to taste better.