Hand-brewing coffee skills | do you want to make the outer powder of hand-brewed coffee?

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I have seen a lot of videos and brewed a lot of coffee. I believe everyone is familiar with coffee making. But do you have this question: do I have to make coffee powder on the outside? Do you want to rush to the outside for steaming and water injection? On this issue, today the editor is going to talk about it in two parts.

§1 | steaming

The general method of steaming and injecting coffee by hand is to inject water around the circle from the center to the outside, so should we directly inject water to the outside to infiltrate the coffee powder? Or in the center of a small area of water injection, the use of water spread to the periphery to infiltrate coffee powder? What is the effect of the two on the flavor of coffee? With this question, let's do it in practice.

We used coffee beans with shallow, medium and deep roasting degrees to do this cooking experiment to explore whether steaming and water injection can wet the flavor difference of the peripheral coffee powder. The reason for choosing three roasting degrees is that for coffee beans with different roasting degrees, the exhaust and water absorption rates are different, and the difference of steaming state can be observed.

After steaming, the normal two-stage extraction is adopted to keep the method of water injection consistent.

Test 1: Sidamo Sakuran shallow baking

Test 2: baking in Yemeni Moka Matali

Test 3: Sumatran gold manning deep baking

Grass flavor and underextracted green and acid were found in the non-peripheral steamed coffee tested in the first two groups, but the effect on the third group was not obvious (deep-roasted coffee exhaust quickly, moisture passed quickly between powder grains). Through the test, it is found that the effect of wetting to the outer powder layer on the flavor is mainly reflected in the uneven extraction caused by the difference in water absorption time of coffee powder in the preparation stage of extraction. The purpose of steaming is to quickly infiltrate all the coffee powder, so that the coffee powder can be evenly watered and vented in the nearest time.

In the group without the outer ring, because the water permeates from the inside to the outside, when the coffee powder in the center reaches the infiltration state, the coffee powder in the periphery just begins to soak in water, which results in the inconsistent extraction rate, especially the light and medium roasted coffee will have the taste of green and insufficient extraction.

And the water injection around the outer ring steaming will appear a phenomenon, that is, the water permeates from the outside to the inside, the central coffee powder exhaust is blocked, will exhaust upward, it looks like a steaming failure.

The key to adopting central water injection is to make water moisten all coffee powder as quickly as possible, so as to achieve the goal of "fast". During water injection, there is little difference between infiltrating into the periphery through small-scale water injection and directly injecting water into the periphery, and the problem of lack of steaming can also be made up for by slightly prolonging the steaming time.

It should be noted that if small bubbles appear continuously in the same place during water injection in the middle, it means that this part is not steaming enough, the strength of the water can not reach the bottom of coffee powder, and coffee powder exhaust hinders in the process of water infiltration. After that, the extraction rate can be improved by quickly and forcefully rotating water injection and "stirring" to make the bottom coffee powder tumble.

§2 | treatment of peripheral coffee powder during formal extraction

We have emphasized in past articles that brewing should not go around the outer circle, so as not to "flush the filter paper", that is, the water breaks through the coffee powder layer and washes the filter paper, causing the water to slip away from the filter paper, so that the coffee will be insipid.

Inject ↓ around the central "one-dollar coin"

Water injection ↓ around the periphery

And the water rushes to the outer layer, which will concentrate the coffee powder in the middle of the filter cup, causing the coffee to be soaked without proper tumbling extraction, which is easy to cause the coffee to have water taste and astringent taste.

If you are worried that the powder in the outer ring will not be extracted and the coffee will not taste good, think about it from another angle-why bother with that small circle of coffee powder? Direct water injection to the periphery is a risky method, the editor does not recommend ~ you can quickly circle, pull up the water to roll to let the peripheral coffee powder stir into the center, but be careful not to excessively!

Finally, there are some tips to cook the outer coffee powder, that is, shaking cups and stirring. The two methods mainly deal with lightly roasted or finely ground coffee. Through these two methods, all coffee can be extracted effectively. Shaking the cup and stirring during steaming can accelerate the exhaust and infiltration of coffee and avoid uneven steaming / insufficient steaming due to slow water infiltration. Stirring in the extraction and shaking the cup at the end of the extraction can improve the extraction rate (we should also pay attention to the extraction), speed up the launching speed and avoid soaking for too long.

The above are some explorations and suggestions for the treatment of peripheral coffee powder. I hope they will be useful to you.