What is Coffee Silver Skin? Is It a Protective Membrane? Does Coffee Bean Silver Skin Affect Taste? It's a Fine Line

FrontStreet Coffee - Introduction to Coffee Silver Skin

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During the roasting process of natural-processed beans, the silver skin on the surface falls off along with the moisture being expelled. Natural-processed beans have relatively more external silver skin, which is removed more thoroughly during roasting, so there's relatively less of it during grinding. Of course, this is directly related to the roast degree - the deeper the roast, the cleaner the silver skin removal.

The silver skin in the crevices of washed-processed beans cannot easily fall off and remains in the center. Washed-processed beans have more internal silver skin, and quite a bit remains after roasting, appearing more during grinding.

Through brewing experiments, it was discovered that silver skin has a taste similar to Ku Ding tea, with a slight sweet rice flavor. The tea-like sensation is obvious, while the bitterness is not prominent.

So does it affect the flavor of coffee?

If the silver skin is not expelled in time, it will be scorched by the high temperature in the roasting drum. When silver skin that has been obviously scorched during roasting is extracted under the same conditions, you will feel astringency. Most silver skin is not removed during the roasting stage.

During the processing of washed-processed beans, there is a long soaking period, during which the silver skin separates from the coffee beans. When the parchment is finally removed, the outer silver skin is peeled away along with it, leaving very little silver skin remaining on the surface of washed green beans.

Natural-processed beans are the opposite - the fruit skin and pulp remain attached to the outside of the beans, and the silver skin adheres more tightly to the coffee beans. When the parchment is removed, it doesn't fall off easily, so natural-processed green beans still have a lot of silver skin attached to their surface.

The silver skin in the crevices participates in fermentation during the initial processing stage of the green beans, carrying regional flavor characteristics and generally having a sweet sensation. After roasting, the silver skin in the crevices and the coffee beans themselves together build a complete origin flavor profile.

Silver skin actually has a significant impact on the flavor of coffee beans. The shorter the contact time between shed silver skin and green beans during roasting, the better. If this layer of silver skin is not expelled in time, it will immediately be scorched by the high temperature in the roasting drum, penetrating the expanding beans and making the coffee taste bitter with a burnt flavor. If the silver skin participated in fermentation during the processing of the green beans, the roasted silver skin will taste sweet.

During the brewing process, the remaining silver skin in the crevices of coffee does not significantly affect the taste of the coffee. You will find that whether the coffee grounds contain silver skin or not does not have much impact on the overall flavor. Natural-processed beans have less silver skin, which is not obvious during tasting, while washed-processed beans have more silver skin, which enhances the barley tea sensation in the aftertaste, rather than bitterness.

Therefore, it's not necessary to filter out the silver skin during brewing - keeping it can actually add layers of complexity. Appropriate amounts of silver skin can enhance the flavor and highlight regional characteristics.

Knowledge Point:

The so-called coffee silver skin is the final protective layer covering the surface of the coffee beans that we ultimately consume. It remains attached to the green coffee beans in their raw state.

In Summary:

FrontStreet Coffee is a coffee research hall, happy to share coffee knowledge with everyone. We share without reservation, only hoping to help more friends fall in love with coffee. Every month, we hold three coffee promotion events with significant discounts. This is because FrontStreet Coffee wants to let more friends enjoy the best coffee at the lowest possible price, which has been our mission for the past 6 years!

Important Notice :

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