What is Crema in espresso? Can hand-brewed coffee wash out grease? What is the role of grease?

The golden Crema floating on the surface of espresso will improve the taste of the coffee, make it more mellow and have a longer finish. And Crema is the product of pressurized extraction, which is the "soul" that hand-brewed coffee cannot have.

Although hand-brewed coffee can not have the same rich Crema, it is possible to make hand-brewed coffee have the same effect. Because Crema is just an appearance supported by carbon dioxide, whether it's mellow or aftertaste, what really works is the oil that wraps carbon dioxide-water-soluble fat from coffee beans. When the espresso leaves for a long time, the foam breaks and dissipates, and we can see the obvious floating matter on the surface of the coffee liquid, and it is the oil body.

But I believe that we can rarely see oil on the surface of hand-brewed coffee, it is real, just because the quantity is too rare, so it can not be obviously detected by us. And the initiator of the problem is "filter paper", because its filtering performance is so strong!

For example, when we use instruments such as Philharmonic pressure, French pressure pots, siphon pots and so on to make coffee, the individual coffee they extract has obvious grease, naturally because their filtration performance is not so good, and the material passing rate is higher. In addition to grease, because of the large gap, some fine powder will also be added to the coffee liquid through the filter, so the coffee liquid looks relatively turbid.

On the other hand, there is no oil floating, the soup color is transparent and bright, forming a completely different contrast. And this is the effect of filter paper. (this is not to say that the filter paper is not good, each has its own advantages.) so, if we want to have the same amount of fat in hand-brewed coffee, it is very simple! You only need to replace the filter paper with extremely strong filter paper with instruments with less excellent filtering performance, isn't it? then the question comes again, which utensils can retain the grease of coffee?

First, flannel filter cloth before the invention of filter paper, flannel filter cloth is the mainstream hand coffee filter. Flannel filter cloth is a fabric made of coarse wool. because the density between the gaps is not as high as filter paper and the holes are not as small as filter paper, it does not filter out too much coffee grease. The coffee brewed out has a very mellow taste and a stronger aroma.

Second, non-woven filter paper non-woven cloth is a kind of cloth made of composite fiber through special technology, also known as non-woven cloth. Compared with conventional wood pulp filter paper, the gap of non-woven fabric will be larger. Insoluble substances such as grease can also pass easily. So now many friends will use non-woven fabric to make the coffee more fragrant.

However, it should be noted that because of the material of the non-woven filter paper, it is very difficult to shape, so we need to wet it with water immediately after folding and stick it to the filter cup. And it is difficult to fit the filter cup, after all, compared with the filter paper, its adsorption capacity is not so strong, so we had better use hot water for wetting. Or you can just use coffee powder to hold it down.

Metal filter is also a filter that can release oil, but compared with the former two, it will be more difficult to brew, and the conventional brewing method needs to be changed to extract a pot of delicious coffee.

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