Coffee review

What's the taste of the hard skin of coffee beans? Will it affect the flavor of coffee?

Published: 2024-04-19 Author:
Last Updated: 2024/04/19, Sometimes, when we grind the coffee beans into powder, they will be mixed with some yellow and white crumbs. Some friends may also wonder, what are these white crumbs? Why are there so many beans while others can't be seen at all? If you don't pick it out, will it affect the taste of the coffee? The last of the coffee beans

Sometimes, when we grind the coffee beans into powder, they will be mixed with some yellow and white crumbs. Some friends may also wonder, what are these white crumbs? Why are there so many beans while others can't be seen at all? If you don't pick it out, will it affect the taste of the coffee?

The last "dress" of coffee beans

These white crumbs, which are conspicuously mixed with coffee powder, are actually the silver skins of coffee beans and the last "clothes" of raw coffee beans before they are roasted in the oven.

Qianjie has shared about the structure of coffee cherries, which are peel, pulp, pectin layer, parchment, silver skin and coffee beans. If we look at the raw beans, we can find that the silver skin treated by the sun is generally yellowish brown, while the ones washed by water are generally rice-white, translucent, tightly wrapped in coffee beans. This layer of silver skin, like peanuts, cannot withstand the excessive expansion of beans during baking.

Since it has been separated, why is there still such a thing?

Although the silver skin will fall off during baking, some coffee beans still have a little silver skin, and the amount of silver skin remains has a lot to do with the way coffee beans are handled. If you often buy different kinds of coffee beans, you will find that some beans have a "white line" in the middle, while others do not.

You can look at the bottom picture of the front street. On the surface, the biggest difference between the two kinds of coffee beans lies in the "white line" between the beans.

This is because the silver skin of the coffee beans is relatively intact during the sun treatment, and can be peeled off by a whole piece during baking, leaving only one left in the heart of the beans. On the other hand, the washed coffee beans cannot retain their complete silver skin like the sun, so they will only detach from a small piece of land when baking, and the remaining silver skin in the middle will become what we see as the "white line".

Therefore, the sharp-eyed partner will roughly judge whether the bean is sun-cured or washed by whether the bean has an obvious "white line".

The above are the cross sections of three different treatments of coffee beans, it is not difficult to find that each treatment will have a silver skin, and the silver skin is more likely to be washed beans.

Will silver dandruff affect the flavor of coffee?

This should be the most curious point for many friends. Qianjie baker has prepared a large bag of silver skin. Without saying much, the "silver skin family bucket" will be opened immediately! Qianjie will use hand flushing, tea bags and coffee machines to extract and taste what silver skin tastes like. As there is no specific instructions on what kind of beans and baked silver skin, so this experiment is to "match" silver skin. )

The hand flushes the silver skin:

Qianjie uses a skin-water ratio of 1:50, that is, 6g of silver skin is injected with 300g of 90-degree hot water. The silver skin water boiled out smells very similar to Xuanmi tea, but tastes more like wheat. Although the overall taste is thin, it is very soft and smooth.

Yinpi tea:

Qianjie took out a disposable tea bag, filled it with 3 grams of silver skin, filled the cup with 210g 95 degrees hot water, soaked for 15 minutes and then began to taste. Although the soaked Yinpi tea is not as fragrant as brewed, it tastes more like Kuding tea, smooth and delicious without astringency, and feels good.

Italian coffee machine high pressure extraction:

Because the silver skin itself is an expanded and loose structure, it is afraid that it will spray crazily under high pressure, so Qianjie uses a shunt handle for extraction. Extraction parameters, use 4 grams of silver skin, 12 seconds to extract 36 grams of silver skin concentrated juice. (too many powder bowls can't fit, so it's no use putting on a powder hammer.)

Although the flow rate of silver skin water is very fast, it does not pour down like turning on the faucet. From the point of view of appearance, the silver skin tea made in this way is very dark, which is very similar to that of deep drying. Taste, first a strong aroma of camellia, followed by a brief bitter feeling, the aftertaste after swallowing is super long-lasting (seven or eight minutes).

Through the three ways of extracting and tasting the silver skin, the results tend to be consistent. The flavor shown by the silver skin is almost wheat fragrance and Xuanmi tea, and there is no frowning taste, and the imagined astringency is not drunk at all. So we can know that the residual silver skin of coffee beans will not have a negative impact on coffee, but can add more layers to coffee.

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