[technical post] three principles of hand-brewing coffee injection

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The main key role of hand-made coffee is the filter cup. Through the unique function of the coffee filter cup, we only need a simple water supply action to extract the substance from the coffee particles. Next, we will follow the principle from shallow to deep, and with you, we will explain step by step why we have to do so.

Let's go! Peel onions to uncover this string of coherent key points.

The three principles of invincibility

one

Each time the water supply should not exceed the amount that can be absorbed by the particles.

As you all know, coffee particles contain a lot of irregular space like a beehive, and when we give hot water, we do a move to absorb and exhaust water. What is meant by "do not exceed the amount that the particles can absorb"?

It is very simple to regard the part of the particles as individuals. The internal space of each coffee particle is limited and cannot absorb a large amount of water. During brewing, the particles will come into contact with hot water, the woody fibers of the particles begin to expand, and the hot water gradually enters. Push the gas outward, and the condition of the particles cannot be drained, if too much water is given at this time. It is obvious that the particles will surface very quickly and cannot be extracted, which is equivalent to soaking the draught particles in the water, and the coffee will be mixed and astringent, so every time the water supply needs to be given a reasonable amount of water, this is one of the principles.

two

The use of penetrating water column so that each water supply can allow undrained particles to eat water.

Generally speaking, a penetrating water column means that in the process of water supply, it is expected that every time the water supply is supplied, the water column can pass through the powder layer that has already been drained before, so that the unabsorbed particles in the lower layer begin to draw water. Assuming that it cannot reach the ideal state, it means that each time the water is given only to allow the previous particles to eat water repeatedly, which is equal to too much water supply, which echoes with the first point. Cause excessive extraction, and the bottom of the powder layer due to water absorption and heavy deposition can not do proper disturbance and tumbling, resulting in excessive soaking, will produce miscellaneous smell and astringent feeling, this is the second point.

three

Let the particles do not rest in the water, each time the amount of water supply is larger and more than the previous one.

In fact, it is not difficult to make a good cup of coffee. It is much easier to understand the principle of the combination of coffee and water. Two of the three major directions of water supply have been revealed. The word "excessive immersion" is repeatedly mentioned in the previous text, that is, the third key point.

The reason is very simple, just like cooking rice, boiled noodles, fried steak, steamed fish, fried vegetables, etc., everyone does not like undercooked or overcooked, because it will not taste good, will not be delicious, or even can not eat, the food is like this, the same is true of making coffee.

How to keep the particles from standing still in the water? Why does the water supply need more and more each time? Now the structure of particle draught should be more and more solid, we will use the mode of water supply combined with the way of particle draught to discuss this key point.

When the particles come into contact with the hot water we give, there will be two separate things, the particles absorbing water and pushing the gas out. Now let's talk about the two topics separately.

(1) the object will become heavier if it continues to absorb water, and the coffee particles are no exception. The particles with rising weight will sink, and the relatively light ones will continue to stay on top. When the particles in the filter cup are gradually saturated, the specific gravity will be larger than the water and will fall to the bottom of the filter cup.

(2) because the exhaust between the particles will push each other to create a space, and the state of the particles after absorbing water and the disturbance caused by the water supply will cause the so-called potential difference, the reason is that the coffee particles in the filter cup can not have different weight of the same grain, so the heavier ones are at the bottom and the lighter ones are at the top.

Now it is more clear that the relationship between particles and water, heavier particles will be deposited at the bottom, if the amount of water supply can not become larger and larger, the particles accumulated at the bottom can not be disturbed, continue to soak, for a long time will become the so-called excessive immersion; remember the first element? The amount of water should be appropriate, otherwise there will be too much water supply, particles soaked for too long, cooking mixed flavor, this is the second kind of excessive immersion.

The above three main points are the general principle of giving water, and each point will be related to each other. this is the so-called detail. when the devil hidden in the details is caught, it is easier to clarify uncertain concepts and apply them to brewing and theory. the world of coffee becomes clearer, connecting more and more clues, and then stringing each clue together. The serial tool is the key ── technique that will be explained immediately.

Article source: "this is the right way to make coffee: 100% invincible hand brews coffee, no matter how good it is!" "