Many friends may find that when grinding coffee beans into powder, there are some white crumbs in the powder bowl in addition to the coffee grounds, what kind of species are these white crumbs, will it affect the flavor of the whole cup of coffee, do you need to pick it off? 
The "skin" that is sandwiched inside the bean body
These crumbs, which are incompatible with the coffee grounds, are actually the silver skin that wraps the coffee beans, and they are also the last coat of green coffee beans after processing.
Like peanuts, this coat will wrap tightly around the core until the beans are roasted, unable to withstand the expansion of the beans and detached. If it's detached, why does it still appear when grinding?
This is going to be a little secret recipe for sharp-eyed friends, is there a friend around you who can distinguish the processing method of coffee beans at the first glance of coffee beans? That's right! It has a great deal to do with the treatment!
The following two are coffee beans that have been processed differently, and the only difference between them is a "white line" in the middle, and this "white line" is the silver skin remaining on the coffee beans. 
The coffee beans on the left are traditionally sun-treated, and the silver skin of the coffee beans is relatively intact after sun-drying treatment, which can be removed in one piece during roasting, leaving only a little bit in the center. The coffee beans with white lines on the right are traditionally washed.
Washed coffee beans are not processed to retain their silver skin intact like the sun is burning, so when roasting, they peel off little by little, and the silver skin that does not come off in the middle forms a white line.
Above are the cross-sections of coffee beans with three different treatments, and we can see that each treatment will leave a certain amount of silver skin, just a difference between more and less, and there is a high probability that there will be more silver skins in washed beans. Does silver shavings affect coffee flavor?
This should be the point that many friends are most worried about, and Qianjie has done several different experiments before.
Three different experiments, but the results are the same, the flavor of the silver skin is almost the sweetness of corn and wheat. From this, we can conclude that Qianjie has played the silver skin thoroughly, and the silver skin does not have a negative impact on the overall flavor, but is a bit like fruit peel tea, which adds a certain layer to this cup of coffee.
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