What is the effect of the residual silver skin of coffee beans on the flavor of coffee? The effect of silver skin of coffee beans

Guide reading

Silver skin is the last "protective film" of coffee beans. Usually, when the coffee beans are processed, the sheepskin (endocarp) will be shaved off, leaving only a thin layer of silver skin wrapped in raw coffee beans.

We can also find traces of silver skin in some ripe coffee beans, and we can also see some white crumbs after grinding coffee powder, which is the remaining silver skin, so does it have an effect on the flavor of coffee?

Why are silver skins left on coffee beans?

In the process of roasting coffee beans, the silver skin attached to the bean surface will fall off. But some coffee beans fall off more completely, while some coffee beans are still left in the seams, forming a "white line". This has something to do with the way coffee beans are handled.

The silver skins of sun-treated coffee beans remain intact when they are raw, so the whole piece of silver skin falls off completely during baking (there will also be trace amounts of silver dandruff). On the other hand, the silver skin of the washed coffee beans is not complete, and the silver skin is fragmented and shedding when baking, and some of the silver skins in the middle of the coffee beans are more difficult to fall off, forming a "white line" in the ripe beans. Therefore, the processing mode of coffee beans can also be preliminarily judged by using this characteristic of cooked beans.

Sun beans on the left and washed beans on the right

Will silver skin affect the flavor of coffee?

In the daily brewing of coffee with more silver skin, the coffee has an astringent and rough taste, so it is inevitable to think that it is caused by silver skin. In order to test whether the residual silver skin has an effect on the flavor of coffee, Qianjie did two comparative experiments.

Asalia, Kenya, which is washed in Qianjie this time, will have more residual silver skin of this bean, one group grinds normally, and the other group cleans up obvious silver dandruff after grinding for intuitive comparison. The cup test and hand brewing were used to compare the effect of silver skin on coffee.

The cup test is to reduce human interference to test the effect of silver dandruff on the flavor of coffee! Hand brewing is the actual effect of silver skin on the coffee we brew! In this way, the influence of coffee silver skin can be more clearly understood by comparison. )

By comparison, there is a lot of silver dandruff left in washing treatment.

In the flavor feedback in the cup test, the two groups showed the same flavor in the first two cups, bright citric acid and small tomatoes. With the extension of soaking time, the cup with silver skin showed a slight ginkgo flavor, which appeared rough and hindered the mouth. In the medium temperature stage, there is a significant difference in taste between the two cups.

At the same time, the front street brewed Kenyan coffee with silver dandruff and silver dandruff by hand. After brewing, the powder layer with silver skin group is covered with silver dandruff, while the powder layer with silver skin group is cleaner coffee particles.

In the flavor feedback of hand-brewed coffee, the flavor of the two groups can not be said to be very similar, can only be said to be exactly the same, while in the taste, there is basically no difference in the high temperature stage. As the temperature dropped, there was no difference in taste.

Conclusion

The performance of the silver skin left in coffee beans (especially washed beans) will not have much impact in hand brewing, because the time is relatively short, the amount of silver skin is very small for the whole, and the coffee brewed by hand will not have a bad taste of silver skin. On the other hand, the taste of coffee will be affected by soaking for a long time.

Of course, if you still care about the white crumbs, you can gently shake the coffee powder after the coffee beans have been ground, and the lighter silver skin will float on the surface. Just need an air pump to gently blow the silver shavings off the surface.