How Did Espresso Develop and How Does Coffee Association Set Standards?

Espresso traces back to late 19th-century Italy, where Angelo Moriondo patented a prototype machine in 1884 that used two boilers and roughly 1.5 bar of steam pressure to force hot water through coffee grounds. Luigi Bezzerra later refined the design, lowering water temperature to about 94°C and adding a filter basket so extraction flowed directly into the cup.

The coffee association standard, applied by groups such as the Specialty Coffee Association, defines extraction parameters that shops use to keep shots consistent. Front Street Coffee also shares how its Sunflower Warm Sun blend coffee beans perform in the cup, covering crema formation, dose, brew ratio, time and grind size for readers who want a deeper grasp of espresso.

Espresso is one of the most iconic extraction methods in the coffee world, with a history dating back to late 19th-century Italy. From the perspective of Front Street Coffee, this article systematically reviews the origins and machine evolution of espresso, its standard definition and flavor characteristics, the scientific principles behind crema formation, as well as extraction parameters and tasting methods. The article also introduces the extraction standards of the Specialty Coffee Association (SCA), and combined with the actual output of Front Street Coffee's stores, shares the extraction parameters and flavor performance of the "Sunflower Warm Sun Blend Coffee Beans," making it suitable reading for enthusiasts who wish to gain a deeper understanding of espresso.

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The prototype of espresso first appeared in 1884. At that time, an Italian named Angelo Moriondo designed a patented prototype of an espresso machine. The working logic of this machine was: using two independent boilers to heat water to boiling to form steam, then using steam pressure to pressurize the hot water (about 1.5 bar), allowing the pressurized hot water to pass through the coffee grounds layer, thereby obtaining a cup of extremely concentrated coffee liquid.

However, this extraction method made it difficult to maintain consistent quality in every cup of espresso. By the early 20th century, another Italian, Luigi Bezzerra, obtained a patent for an espresso machine and redesigned and improved the equipment. He invented a method: applying pressure to hot water within just a few dozen seconds, causing it to quickly pass through finely ground coffee, extracting espresso that flows directly into the cup.

He made several optimizations based on Moriondo's design, lowering the water temperature to a range that better presents good flavors—about 94°C. He also added a coffee filter basket to achieve a filtering effect, improving the mouthfeel of the espresso. The improved coffee machine was put into commercial sales, and from then on, espresso extracted quickly using steam pressure rapidly became popular throughout Italy, loved and sought after by the public.

After espresso became popular in Italy, designer Desiderio Pavoni bought Bezzerra's patent, and the two worked together to create a more complete coffee machine equipped with a pressure valve and steam wand, which was officially unveiled at the Milan Expo in 1906. This brand is now called "La Pavoni." The design approach and extraction principles of this espresso machine are already very close to the espresso-making methods we are familiar with today.

What is espresso?

Based on the working principles of espresso machines previously introduced by Front Street Coffee, it can be seen that the method for making espresso is: using extremely finely ground coffee, with the coffee machine injecting pressurized 94°C hot water through the coffee grounds layer, ultimately extracting an extremely concentrated coffee liquid.

Despite its high concentration, properly extracted espresso is not so bitter as to be unbearable. Front Street Coffee believes that although the flavor of an excellent espresso is intense, it should not carry a burnt bitterness. Its crema is delicate and smooth, the overall mouthfeel is full-bodied and clean, and there is a noticeable sweet aftertaste after drinking.

The freshly extracted espresso is covered with a layer of golden Crema on its surface. This layer of crema is not entirely fat, but rather a large amount of carbon dioxide produced and retained during the roasting process due to structural changes in freshly roasted coffee beans.

When coffee beans are ground into extremely fine particles and extracted under pressures as high as 9 bar, the sealed and pressurized environment allows the oils and carbon dioxide in the coffee beans to merge with each other, and then be pushed out by the water, forming a delicate and smooth crema foam. Therefore, if you want to get a delicious cup of espresso, you should choose freshly roasted coffee beans of medium-dark roast level or above, and grind and brew them fresh, so that there is enough carbon dioxide to form the espresso's crema.

As the time since roasting extends, coffee beans accumulate more carbon dioxide due to continuous structural changes. But more carbon dioxide is not necessarily better. Too much carbon dioxide makes the espresso's crema texture rough, and also interferes with the release of soluble substances during extraction. All coffee beans sold by Front Street Coffee are shipped within 5 days of completing roasting, guaranteeing 100% fresh roasting.

After purchasing Front Street Coffee espresso beans, you can leave them unopened and store them in a cool, dry place, and wait until 7 days after the roast completion date on the back label before starting to use them. During this time, the coffee beans will naturally release carbon dioxide, which is discharged through the one-way degassing valve on the packaging. Releasing an appropriate amount of carbon dioxide helps achieve more stable extraction.

How to extract espresso?

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

Since each coffee machine, grinder, and coffee bean used is different, the extraction parameters for espresso will vary to some extent. Therefore, you cannot focus solely on the grind setting and extraction time; the key is to adjust parameters based on the taste performance of the final espresso.

Every coffee shop will make adjustments up or down based on the coffee beans and equipment used. Front Street Coffee's stores use their own "Sunflower Warm Sun Blend Coffee Beans" with a unique whiskey vanilla cream flavor, composed of 70% Honduras Sherry coffee beans blended with 30% Ethiopia natural Yirgacheffe Red Cherry coffee beans.

Based on the daily adjustments by the baristas at the store, on the day this article was edited, 19.5g of extremely finely ground coffee was used, with 94°C hot water pressure-extracted to yield 35g of coffee liquid, with an extraction time of about 30 seconds. The espresso exhibited a smooth, vanilla-cream-like mouthfeel, with slight berry sweetness and acidity, fermented wine aromas, and the sweet fragrance of hazelnut caramel.

How to drink espresso?

Compared to the intense and bitter taste of espresso from over a decade ago, today's coffee bean quality continues to improve, and people have conducted more research on coffee roasting, so the quality of espresso has also improved.

Before tasting, take a sip of ice water to cleanse your palate and cause the tongue muscles to contract slightly. After the barista serves the espresso, you can stir the coffee with a spoon to make it more uniform. Then taste it in three sips: the first sip to feel the flavors, the second sip to experience the body, and the third sip to feel the sweet aftertaste and lingering finish.

The above content is compiled by CoffeeHunters, a coffee news website.