What is the principle of hand extraction? Is there any way to make coffee?

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What is the principle of hand extraction? Is there any way to make coffee?

Extraction is the process of dissolving a substance in water. The principle of extraction is nothing more than the release of substances needed when coffee powder comes into contact with water.

Steaming is to infiltrate all coffee powder and prepare for the following formal extraction.

Hand-brewed coffee is a simultaneous process of flavor extraction and filtration, and the extraction takes place around the position where the water is poured. The key lies in how to control and balance the amount of extraction of various ingredients in roasted beans to prepare coffee.

Medium and deep baking manning VS shallow baking ninety + candles

The degree of grinding is the same, little Fuji ghost teeth 4

Water temperature 90 degrees, water injection

When we hand-feed water for the first time, we will see the coffee powder expand, this process is in the exhaust, in this process, the coffee has been fully prepared for extraction.

"stew": to help exhaust

A series of chemical reactions and physical changes will take place in the roasting process of coffee beans from raw beans to ripe beans. After a certain degree of roasting, a large amount of gas will be accumulated in the coffee beans. Several people think it's carbon dioxide.

The bottom layer because the coffee powder is in full contact with water, resulting in the active dissolution and diffusion of coffee ingredients, but the upper layer is mixed with the gas discharged from the coffee, so the coffee is not in full contact with water. So even if you put in enough coffee powder, some of the coffee ingredients can't be completely dissolved.

Diffusion

This process is diffusion, and the side is like this!

A careful observation of the coffee powder floating on the water shows that it has been divided into two layers.

In general, coffee beans with a deeper roasting degree accumulate more gas, obviously have a high water absorption rate, and have a particularly thick powder layer; for light-roasted coffee beans, they do not have that much gas, and the powder layer is not so thick.

Stirring: accelerating dissolution and diffusion

Stand still for a while and begin to stir the coffee powder. The coffee powder begins to dissolve and spread.

In order to fully form dissolution and diffusion, it is sometimes stirred in the filter cup with a spoon. Stir with a spoon and mix the layered parts again so that the coffee and water can be fully contacted.

After stirring, the light baked ninety + candles will sink to the bottom faster, and some of the medium and deep Mantenin will float.

Therefore, for medium and shallow roasted coffee beans, in the process of brewing, the coffee powder sank more time on the surface of the water, and the resistance of water flowing out of the filter cup became greater. In order to better control the extraction time, it is recommended to use a filter cup with a faster flow rate. For example, the V60 ~ (th) key Diamond Cup

If the water is used to hit the coffee powder and make the powder layer tumble, the water injection itself is to fully stir the water and coffee, so as long as the water and coffee can be stirred well, it can also be stirred without a spoon, and the coffee powder can also be in full contact with water.

First water injection

Inject it from the center with a small column of water, and then slowly wind it out, just like gently laying a layer of water on the noodle, although it is a small column of water, please be careful not to slow down, because once the speed is too slow, the column of water will flow in a single direction, so that the draught of the powder layer is uneven.

After the end of the first water supply, the coffee powder particles will push each other due to exhaust, resulting in expansion. When the expansion reaches the highest point or is about to rest (the surface water will slowly dry), this is the time for the second time to add water.

Second water injection

The second water injection also starts from the middle, injecting a small water column into the bottom of the powder layer. In order to concentrate the penetrating force of the water column, the range of movement around the water column should be small, about the size of an one-dollar coin, and then go out. At the beginning of the second water supply, we should pay attention to the amount of water, and try not to exceed the height of the powder layer, that is, when the water column is wound close to the filter paper, the water supply can be stopped.

In the initial stage of water supply, because most of the coffee powder particles are in a state of exuberant exhaust, the air produced by them will soon flow to the edge of the filter paper, so if you give too much water at this time, instead of bringing water to the bottom, you should use a small water column to speed up the circle to avoid these problems.

As the thicker powder layer on the edge of the original filter paper becomes heavier because of the draft, and as the water level falls and becomes thinner, the water level drops to half and the third water injection can be carried out.

The third water injection

From the third water supply, it is necessary to observe the extent of the decline of the water level, also from the center of the water supply circle, the amount of water should not exceed the height of the powder layer, then it will also be observed that the proportion of foam has already occupied the surface, and the third water injection will increase the tumbling of coffee granules, let all the deposited particles tumble, and then dissolve the soluble matter.

The rolling particles will start to rest because they stop adding water, and at this time they have to rely on the velocity caused by the falling water level to make the coffee particles produce friction, so once the addition of water stops, the coffee powder particles will sink, causing blockage, so pay special attention to the rhythm of adding water.

If the water is cut off too many times, it is tantamount to letting the coffee powder particles soak in the water all the time, which will lead to the astringent and miscellaneous taste of the coffee extract at the end.