American Coffee beans Italian making skills _ what coffee beans can be made American _ how to make American delicious

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Espresso: Chinese people generally call it espresso.

Made from roasted and ground coffee powder and water.

High pressure, high temperature, quick extraction of small volume coffee.

A heterogeneous drink: a drink containing solids, liquids, and gases.

The components of espresso are water-soluble solids, emulsified grease, suspended fine powder and foam.

● crema

It's actually a foam layer.

The formation of the foam layer requires bubbles, as well as compounds or particles surrounding the bubbles.

Bubbles are caused by the presence of carbon dioxide in coffee beans, and the water pressure of the espresso machine increases the solubility of water to carbon dioxide, thus dissolving more carbon dioxide than at natural pressure.

But bubbles dissipate easily, such as when we open a bottle of Coke or beer, the rising foam in the bottle disappears after being placed for a while.

The foam layer of a normally extracted espresso lasts longer because crema contains not only bubbles but also compounds such as melanin and protein. Some of them repel water (that is, hydrophobic), so they are close to the gas, and these substances are adsorbed on the bubbles to form a bubble layer.

● [free amino nitrogen compounds such as amino acids and proteins in coffee beans react with carbohydrates such as sugars during baking to form a brown and complex macromolecular compound-melanin. ]

In addition, there are other non-polar substances in coffee that repel water, such as oil / fat. Fat is the solid form of oil, which usually destroys the bubble layer. Arabica coffee beans contain more fat than robusta beans, so the crama of espresso made from Arabica coffee beans is thinner than that of robusta beans. )

●, no matter what kind of extraction method

The extracted coffee contains water-soluble and insoluble substances.

Including solids, gases and oils.

As shown in the picture above, oil is insoluble in water.

During ● espresso machine extraction, the pump pressure of 9bar emulsifies the insoluble oil.

Emulsification refers to two immiscible liquids (such as water and oil), under the action of appropriate surfactants, through strong stirring, one liquid is dispersed in another liquid to form an emulsion. ]

During the extraction of espresso, some tiny fragments of coffee powder are pushed out of the coffee pressed powder and together with the oil to form a brewing glue, thus contributing body to espresso, while locking in a lot of aromatic substances until we drink espresso.

To sum up, after espresso is made, the black liquid is covered with gas, fine powder and emulsified oil.

Having said so much, what on earth is this little trick to share today? Please take a look at the following picture:

Yes, when making American coffee, you first fish out espresso's crema and then pour it into the water. I've tried. Try it if you don't believe me. The effect of this technique is particularly effective when making espresso using particularly fresh espresso beans.

● American coffee bean brand recommendation

The best-selling American coffee beans roasted on Qianjie Coffee: Yega Chuefei Coffee, Golden Manning Coffee, Brazilian Coffee and so on are fully guaranteed in terms of brand and quality. And more importantly, the performance-to-price ratio is extremely high, a pack of half a pound 227 grams, the price is only about 70-90 yuan. According to the calculation of 15 grams of powder per cup of hand-brewed coffee, 15 cups of coffee can be made in a bag, and each cup of American coffee costs only about 5 or 6 yuan, which is very cost-effective for cafes to sell dozens of yuan a cup.

END Qianjie Coffee: Guangzhou bakery, small storefront but a wide variety of beans, you can find a variety of unknown beans, but also provide online store services. Https://shop104210103.taobao.com