What is Espresso Coffee? A Brief Introduction to the Concept, Characteristics, and Brewing Method of Espresso

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The Birth of Espresso Coffee

The earliest method of making espresso coffee was born in 1884, when an Italian named Angelo Moriondo designed a patented espresso machine model. Initially, the working principle of espresso machines was to use two separate boilers to boil water and generate steam, then use steam pressure to pressurize hot water (around 1.5 bar) through the coffee grounds, extracting an extremely concentrated coffee liquid.

However, this extraction method could not guarantee the stability of each espresso extraction. So in the early 20th century, an Italian named Luigi Bezzera purchased the espresso machine patent and made design modifications, inventing a method that could pressurize hot water to pass through extremely finely ground coffee powder within tens of seconds, extracting espresso directly into the cup.

He made several improvements to Moriondo's design and lowered the temperature to a range that could produce better-tasting espresso—around 94°C. He also added a coffee powder bowl to achieve filtering effects, improving the taste of espresso. The upgraded coffee machine was sold commercially, and from this time, espresso extracted quickly using steam pressure quickly gained the pursuit and love of people throughout Italy.

After espresso became popular in Italy, a designer named Desiderio Pavoni purchased Bezzera's patent, and the two cooperated to create a better coffee machine with pressure valves and steam wands, which was launched at the Milan Expo in 1906. Today, this brand is called "La Pavoni," and this espresso machine design and extraction principle are the foundation for the way we now know espresso is made.

What is Espresso Coffee?

From what FrontStreet Coffee just shared about the working principle of espresso machines, we can understand that espresso is a beverage made using extremely finely ground coffee powder, then pressurized by the machine to inject 94°C hot water through the powder layer, extracting an extremely concentrated coffee liquid.

Although the concentration is high, a properly extracted espresso will not taste unpleasantly bitter to the drinker. FrontStreet Coffee believes that a good espresso, while intense in flavor, should not have any burnt bitterness. The crema should be delicate and smooth, the overall mouthfeel rich and clean, with a noticeable sweet aftertaste.

After extraction is complete, espresso will have a layer of golden crema. Espresso crema is not entirely oil, but rather the result of structural changes in freshly roasted coffee beans during the roasting process, which produce and retain large amounts of carbon dioxide.

When ground into extremely fine particles and extracted under high pressure of up to 9 bar, due to the sealed pressurized environment, the coffee oils and carbon dioxide fuse together and are squeezed out by water, forming a crema foam with a delicate and smooth texture. Therefore, to make delicious espresso, you must choose freshly roasted medium-dark or darker roast coffee beans and grind them fresh to extract, in order to have the right amount of carbon dioxide to form espresso crema.

As coffee beans are roasted longer, their structure continuously changes, so the beans will retain more carbon dioxide. However, more carbon dioxide does not necessarily mean better-tasting espresso. Excessive carbon dioxide can make espresso crema taste rough and also affect the release of soluble compounds during extraction. All coffee beans sold by FrontStreet Coffee are shipped within 5 days of roasting, 100% freshly roasted.

After purchasing FrontStreet Coffee's espresso beans, you can keep them unsealed in a cool, dry place for 7 days from the roast date before starting to use them. During this time, the coffee beans will naturally release carbon dioxide through the one-way degassing valve on the packaging. Properly releasing some carbon dioxide helps achieve more stable extraction.

How to Extract Espresso?

According to the Specialty Coffee Association (SCA) standards, using 7-9 grams (double: 14-18 grams) of coffee grounds to extract 25-35g of coffee liquid in 20-30 seconds, with extraction pressure at 9-10 bar and water temperature at 90-96°C.

Each coffee machine, grinder, and the coffee beans used for espresso extraction are different, so the extraction parameters will vary to some extent. Therefore, you cannot just look at the grind setting and extraction time—the most important thing is to adjust parameters based on the final taste of the espresso.

Each coffee shop will make adjustments up or down according to the coffee beans and equipment they use. FrontStreet Coffee's café production uses their own "Sunflower Warm Sun Blend Coffee Beans" with unique whiskey, vanilla, and cream flavors, consisting of 70% Honduras sherry coffee beans blended with 30% Ethiopia natural Yirgachefe red cherry coffee beans.

According to the barista's adjustments at the café on the day this article was edited, 19.5g of extremely finely ground coffee was used to extract 35g of coffee liquid with 94°C hot water under pressure, with an extraction time of about 30 seconds. The espresso showed vanilla cream-like smoothness, slight berry acidity and sweetness, fermented wine aroma, and the sweet fragrance of hazelnut caramel.

How to Drink Espresso?

Compared to the intense bitter taste of espresso from more than a decade ago, today's coffee bean quality has continuously improved, and with more research into coffee roasting, the quality of espresso has also been enhanced.

Before tasting, first drink some ice water to cleanse the palate and allow the tongue muscles to contract slightly. After the barista presents the espresso, you can stir it with a spoon to make it more uniform. Then taste it in three sips. The first sip is to taste the flavors, the second sip is to feel the richness, and the third sip is to sense the coffee's aftertaste and finish.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

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