Should Coffee Silver Skin Be Removed | Does Coffee Silver Skin Have A Bitter Taste? The Impact of Silver Skin on Coffee Flavor

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Customers often ask, "Your coffee has so much silver skin, don't you screen it out? This silver skin greatly affects the coffee flavor!" Well, FrontStreet Coffee couldn't help but wonder, does silver skin really have such a big impact on coffee?

The Foundation of Great Coffee

A successful cup of coffee begins with meticulous handling of raw coffee beans. Coffee bean processing methods can be divided into natural and washed methods. The specific method used depends on the local climate, environment, and coffee bean characteristics. After coffee beans are processed, they can be roasted and ground. However, what determines a cup of coffee mainly depends on the freshness of the coffee beans. Whether a coffee bean is successfully processed directly affects whether this cup of coffee is worth your praise.

Silver Skin (Chaff)

Inside the parchment, there is an even thinner film wrapping the coffee bean. Due to its glossy and silver-tinged color, people habitually call it "silver skin." This layer of silver skin will fall off during roasting. Usually, when you grind coffee, you might notice some silver fragments in the coffee powder. These fragments are exactly the silver skin that failed to separate from the coffee beans during roasting.

Silver Skin in Different Processing Methods

In "Coffee Coffee," there's a saying: if we roast and heat coffee beans, naturally processed beans will shed much more silver skin, while washed processed beans will shed much less. When we look at the central crease of roasted coffee beans, if quite a bit of white silver skin is retained, it's more likely to be washed processed coffee beans.

Moisture Content

Washed coffee has a moisture content of 12%-13%, while natural (dry-processed) coffee has a moisture content of 11%-12%. General coffee beans show different colors due to their different moisture contents. Higher moisture content appears green or cyan, while less appears brown or nearly white. Therefore, washed coffee beans show a deeper green color.

Integrity of Silver Skin

During the washing process, the silver skin on coffee beans is generally removed, presenting a special luster. However, the natural processing method only removes the coffee husk, leaving the silver skin completely intact.

Roast Degree

Different processing methods use different roast degrees, and their effects are also different. Generally, if washed coffee beans haven't undergone deep roasting, the silver skin remaining in the central line will still exist. Although the silver skin of naturally processed beans remains intact during processing, it disappears after roasting. The deeper the roast degree, the darker the color of the coffee beans.

Naturally processed beans have relatively more outer silver skin, which is shed more thoroughly during roasting, so there's relatively less when grinding. Washed beans have more inner silver skin, and quite a bit remains after roasting, appearing more during grinding. Of course, this is directly related to the roast degree - the deeper the roast, the cleaner the silver skin is shed.

Too much silver skin can cause astringency, but if the silver skin is over-processed from raw beans, it will lead to reduced flavor.

Moreover, the central line of washed beans definitely has silver skin, but the question is whether that part necessarily produces obvious astringency. Don't pick out all the silver skin completely!

Good electric grinders have automatic silver skin removal functions. For hand grinders, first grind at the coarsest setting, blow away the silver skin, then grind finely. Not removing silver skin causes a slight astringency but doesn't affect the overall taste of the coffee.

What Does Silver Skin Actually Taste Like?

FrontStreet Coffee brewed a pot to test - what exactly does it taste like!

Brewing: 90°C water, 1g silver skin, color shows a light golden yellow

Flavor: When drinking, it's like bitter tea (Kudingcha), with a slight sweet rice taste, obvious tea sensation, with no obvious bitter or astringent taste.

Does Silver Skin Affect Flavor?

FrontStreet Coffee conducted a comparison using [Natural Berry Garden] and [Washed Benerfica]:

[Natural Berry Garden]

Water temperature: 89°C

Beans: 15g

Powder-to-water ratio: 1:15

Total time: 1:58 seconds

Method: Three-stage brewing, 30g bloom for 30 seconds, first stage with small water flow, slowly circling to 125g, pause until the liquid level drops to 1/3, then pour water to 225g with larger water flow and faster circling speed

Flavor: Rich berry and fruit wine dry aroma, when sipping starts with strong strawberry and blueberry accompanied by passion fruit, mango and other tropical fruit aromas, middle notes have apricot, peach and grape juice flavors, floral, peach and berry aromas run through the entire palate, with some nutty aftertaste.

[Washed Benerfica]

Water temperature: 90°C

Beans: 15g

Powder-to-water ratio: 1:15

Total time: 2:05 seconds

Method: Three-stage brewing, 30g bloom for 30 seconds, first stage with small water flow, slowly circling to 125g, pause until the liquid level drops to 1/3, then pour water to 225g with larger water flow and faster circling speed

Flavor: Fresh and charming coffee flower with sweet lemon aroma, at first taste you can feel the sweet and sour taste of yogurt, with citrus, fresh lime, bergamot, lychee outlining the entire profile, middle notes appear with orange blossom and peach accents, while the aftertaste brings spice, floral and Earl Grey tea notes.

After brewing experiments, FrontStreet Coffee found that whether to keep the silver skin when brewing doesn't actually have much negative impact on the overall flavor. Natural beans have less silver skin, and it's not obvious when tasting. Washed beans have more silver skin, which enhances the tea sensation in the aftertaste without the legendary bitter taste. When brewing, it's not necessary to screen out the silver skin - keeping it actually adds layers of complexity.

END

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473