American Coffee Bean Espresso Brewing Techniques_What Coffee Beans Make American Coffee_How to Make Delicious American Coffee

Professional coffee knowledge exchange. For more coffee bean information, please follow Coffee Workshop (WeChat public account: cafe_style).

Espresso: Commonly referred to as Italian concentrated coffee by Chinese people.

Made from roasted and ground coffee powder and water.

High pressure, high temperature, and rapid extraction of small-volume coffee.

A multi-phase beverage: a drink containing solids, liquids, and gases.

The components of espresso are: water-soluble solids, emulsified oils, suspended fine particles, and foam.

Crema

Actually a foam layer.

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

The production of bubbles is due to carbon dioxide contained in coffee beans. The water pressure of the espresso machine increases the solubility of water to carbon dioxide, thus dissolving many times more carbon dioxide than under natural atmospheric pressure.

However, bubbles are easily dispersed, just like when we open a bottle of cola or beer, the continuously rising foam in the bottle disappears after a while.

The foam layer of a normally extracted espresso will be more persistent, because crema not only contains bubbles but also compounds such as melanoidins and proteins. Some of these components repel water (i.e., are hydrophobic), so they approach the gas, and these substances are adsorbed onto the bubbles, forming a bubble layer.

【Melanoidins are complex, brown, large molecular compounds formed by the Maillard reaction between nitrogen-containing compounds with free amino groups such as amino acids and proteins contained in coffee beans and carbohydrates such as sugars during roasting.】

In addition, coffee contains other non-polar substances that repel water, such as oils/fats. Fat is the solid form of oil, and fat usually damages the bubble layer. (Arabica coffee beans contain higher fat content than Robusta beans, therefore, the crema of espresso made with Arabica coffee beans is thinner than that made with added Robusta beans.)

Extraction Process

Regardless of the extraction method, the extracted coffee contains both water-soluble and water-insoluble substances, including solids, gases, and oils.

As shown in the figure above, oils are insoluble in water.

During espresso machine extraction, the 9-bar pump pressure emulsifies the non-soluble oils.

【Emulsification refers to the process where two immiscible liquids (such as water and oil), under the action of appropriate surfactants and through vigorous stirring, cause one liquid to disperse in another liquid, forming an emulsion.】

During the espresso extraction process, some extremely fine coffee powder fragments are pushed out from the coffee puck. They form brewing colloids together with the oils, thus contributing body to the espresso while locking in many aromatic substances, which only reveal themselves on the tongue when we drink the espresso.

To summarize, after the espresso is made, the black liquid is covered with gas, fine particles, and emulsified oils.

The Tip

After saying so much, what is the small tip shared today? Please see the picture below:

That's right, when making Americano coffee, first remove the crema from the espresso before pouring it into water. I've tried it, if you don't believe me, try it yourself. The effect brought by this tip is particularly effective when using very fresh espresso beans to make espresso.

Americano Coffee Bean Brand Recommendations

FrontStreet Coffee's roasted best-selling Americano coffee beans: Yirgacheffe coffee, Golden Mandheling coffee, Brazil coffee, etc., all have full guarantees in terms of brand and quality. More importantly, the cost-performance ratio is extremely high. A half-pound 227-gram package costs only about 70-90 yuan. Calculated at 15 grams of powder per cup of pour-over coffee, one package can make 15 cups of coffee, and each cup of Americano only costs about 5-6 yuan. Compared to the price of dozens of yuan per cup sold in cafes, this is extremely cost-effective.

END FrontStreet Coffee: A roastery in Guangzhou with a small shop but diverse bean varieties, where you can find various famous and unknown beans, while also providing online store services. https://shop104210103.taobao.com

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473