Espresso is the base for many coffee drinks, and its evolution has spanned more than a century, from the patented designs of the late 19th century to the modern 9-bar extraction standard. This article will begin with its historical origins, trace the iterative process of Espresso's brewing principles, explain the formation mechanism of Crema and the importance of fresh roasting, and provide SCA extraction parameter references. At the same time, using a properly extracted espresso as a sample, it introduces the complete method from cleansing the palate to tasting in three sips. The article also includes the specific recipe and extraction data of the Sunflower Warm Sun blend coffee beans used in Front Street Coffee store production, for coffee lovers' reference.

The prototype of espresso can be traced back to 1884. At that time, an Italian named Angelo Moriondo registered a patent for an espresso machine. The working logic of this machine was to use two independent boilers to heat water to boiling, generate steam, and then use steam pressure to pressurize the hot water, maintaining a pressure of about 1.5 bar, allowing the hot water to pass through the coffee powder bed, thereby obtaining a cup of highly concentrated coffee liquid.

However, this extraction method made it difficult to ensure the stability of 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: within a few tens of seconds, pressurize hot water so that it quickly passes through extremely finely ground coffee powder, completing extraction and flowing directly into the cup. He made multiple adjustments to Moriondo's plan, controlling the water temperature to a range that better presents good flavor, about 94°C, and adding a coffee powder basket to strengthen the filtration effect, thereby optimizing the taste of espresso. The improved coffee machine was put into commercial sales, and from then on, this espresso made by rapid extraction with steam pressure quickly became popular throughout Italy.

After espresso became popular in Italy, designer Desiderio Pavoni bought Bezzerra's patent, and the two collaborated to create a more complete coffee machine equipped with a pressure valve and steam wand, officially launched at the Milan Exposition in 1906. This brand is now known as "La Pavoni." The design concept and extraction principles of this espresso machine also laid the foundation for the espresso-making method we are familiar with today.

What is espresso ?

From the working principle of the espresso machine just shared by Front Street Coffee, we can know that espresso is made by using extremely finely ground coffee powder, with the coffee machine pressurizing and injecting 94°C hot water through the powder bed, extracting a highly concentrated coffee liquid.

Although the concentration is very high, a properly extracted espresso will not be so bitter that the drinker feels uncomfortable. Front Street Coffee believes that although the flavor expression of a good espresso is intense, it should not carry a burnt bitterness. Its crema is delicate and smooth, the overall mouthfeel is mellow and clean, and there will be a clear sweet aftertaste in the finish.

After extraction is completed, the surface of the espresso will be covered with a layer of golden crema. This layer of crema is not entirely composed of fat; rather, freshly roasted coffee beans undergo structural changes during the roasting process, generating and storing a large amount of carbon dioxide within them.

When coffee beans are ground into extremely fine particles and extracted under pressure 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 they are pushed out by the water, forming a delicate and smooth crema foam. Therefore, to make espresso taste good, you should choose coffee beans that are freshly roasted and at a medium-dark roast level or darker, and grind and brew them fresh, so that there is enough carbon dioxide to form espresso crema.

The longer the time after coffee beans complete roasting, the more carbon dioxide remains inside due to continuous changes in internal structure. But more carbon dioxide is not necessarily better. Too much carbon dioxide will make the crema texture of the espresso rough, and it will also interfere with the release of soluble substances during extraction. All coffee beans sold by Front Street Coffee are shipped within 5 days after roasting is completed, ensuring 100% fresh roasting.

After purchasing Front Street Coffee espresso coffee beans, you can leave them unopened first, place them in a cool and dry place, and wait until 7 days after the roasting completion date marked on the back label before starting to use them. During this period, the coffee beans will release carbon dioxide on their own and discharge it through the one-way exhaust valve on the packaging. Releasing an appropriate amount of carbon dioxide helps obtain more stable extraction.

How to extract espresso ?

According to the Specialty Coffee Association SCA standards, use 7-9 grams of coffee powder (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.

Different coffee machines, grinders, and coffee beans used will cause certain differences in extraction parameters, so you cannot focus only on the grind setting and extraction time. The most critical thing is to adjust parameters based on the final taste performance of the espresso.

Every coffee shop will make upward or downward adjustments according to the coffee beans and equipment used. Front Street Coffee store production uses its own "Sunflower Warm Sun Blend Coffee Beans" with a unique whiskey vanilla cream flavor, composed of 70% Honduras Sherry coffee beans blended with 30% Ethiopian natural Yirgacheffe Red Cherry coffee beans.

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

How to drink espresso ?

Compared with the strong and bitter taste of espresso more than ten years ago, coffee bean quality today has continued to improve, and with everyone having more research on coffee roasting, the quality of espresso has also improved significantly.

Before tasting, take a sip of ice water to clean your palate and allow the muscles on the surface of your tongue to contract slightly. After the barista serves the espresso, you can stir it with a spoon to make it more uniform overall. 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 notice the sweet aftertaste and lingering finish of the coffee.

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