What makes espresso coffee beans extract so intensely?

Espresso is a small, concentrated coffee extracted under high pressure, and its two defining traits are the golden crema on the surface and an intense, layered taste. The crema forms when dissolved carbon dioxide from roasted espresso coffee beans escapes as pressure drops, creating a stable bubble layer on the liquid.

Bean freshness and roast level determine how thick that crema turns out. Key parameters include dose, yield, and extraction time, and a machine such as the Lelit Bianca lets the barista control pressure and flow. A blend coffee like Sunflower Warm Sun, or single options such as Classic Espresso Blend, gives different flavor directions.

Espresso serves as the base for many fancy coffee drinks; though small in volume, it carries a concentrated essence of flavor. This article focuses on its two core characteristics—the golden Cream on the surface and its intense taste—explaining how coffee bean freshness and roast level affect the crema, and breaking down in detail the key parameters for making Espresso at home or in a café, such as dose, yield, and time. It also introduces the extraction performance of the Lelit Bianca espresso machine and the Sunflower Warm Sun blend used at Front Street Coffee, and recommends coffee beans such as the Classic Espresso Blend and Strawberry Candy Espresso for different taste preferences, helping readers understand espresso comprehensively from bean selection to the final cup.

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Coffee culture is becoming increasingly popular in China, with coffee shops opening on more and more street corners, and espresso—known for being efficient and convenient—is especially favored. A cup of aromatic espresso lays the foundation for all kinds of popular Italian-style drinks. Today, Front Street Coffee will introduce you to the espresso that is considered the "soul" of coffee shops, and just what makes it so unique.

The Core Characteristics of Espresso

Espresso, known in English as Espresso, is a coffee liquid extracted quickly at high temperature by Italians using a pressure-driven coffee machine, and its surface is covered with a layer of golden foam. Different shops use different espresso beans and extraction recipes, so the flavor performance also varies, but a standard cup of espresso usually has the following two characteristics.

Cream

When you order an espresso at a coffee shop, as soon as the barista finishes extracting and serves it, you can observe a thick layer of golden foam floating on top of the liquid—this is what we commonly call Cream.

Coffee beans generate a large amount of gas during roasting, and the high-pressure water flow dissolves out the carbon dioxide. When the extracted coffee liquid returns to normal atmospheric pressure, the liquid can no longer retain all the gas, so countless tiny bubbles surge out of the coffee liquid. These bubbles remain on the surface, looking like a stable "bubble layer." A rich and dense Cream indicates that the coffee beans used to make the espresso were freshly roasted. This is because the gas inside coffee beans is continuously released over time; the farther from the roast date, the lower the carbon dioxide content, and the thinner the foam layer formed during extraction.

If a cup of espresso has no Cream on the surface, it is very likely that the coffee beans have been stored too long, or that the espresso has been left sitting for too long after being made and the foam has already dissipated. The darker the color of the Cream, the more intense the taste usually is. This is because the coffee beans undergo the Maillard reaction at high temperatures; beans with a darker roast level have a darker foam layer and a richer, fuller taste.

High Concentration

A single serving of espresso needs to release a large amount of soluble substances in just a few dozen seconds, so the coffee grounds must be ground extremely fine and evenly. Through the action of near-boiling hot water and 9 atmospheres of high pressure, the concentration of espresso is very high, and all flavors are doubled and concentrated, delivering a strong impact on the palate. After swallowing, the various aromas linger in the mouth for a long time, with a long finish. That is why many coffee shops serve a glass of water alongside a strong espresso.

How to Make Espresso

Many coffee enthusiasts have unknowingly accumulated a lot of coffee equipment at home, and friends who are obsessed with espresso have even stocked up on espresso machines, ready to extract it themselves. Here, Front Street Coffee uses café production of espresso as a reference to briefly explain how to make a shot of Espresso.

The coffee machine used at Front Street Coffee's shop is the commercial single-group "Lelit Bianca," which can adjust extraction by changing pressure, with a maximum pressure of up to 11 bar. A home coffee machine only needs to reach 9 bar of pressure to meet the needs of extraction and milk frothing, and pairing it with an espresso grinder is enough.

Front Street Coffee uses the capacity of a double basket, with a dose of about 18–20 grams, and Front Street Coffee uses 20 grams of coffee grounds when producing. Usually the ratio of coffee grounds to coffee liquid is between 1:1.5 and 1:2.5, and Front Street Coffee's extraction ratio is 1:2, meaning 20 grams of coffee grounds extract 40 grams of coffee liquid. Time is related to the flow rate of the coffee grounds; generally a single extraction is controlled within 20–35 seconds, because within 20 seconds the coffee taste is usually relatively thin, while exceeding 35 seconds makes over-extraction and a burnt bitter taste likely. Most of Front Street Coffee's espressos fall within the 28–30 second range.

Front Street Coffee first wipes the basket dry, turns on the grinder, grinds the amount for a double shot of coffee grounds, places it on an electronic scale and adjusts it up or down until it reaches 20 grams. Then use a tool to distribute the grounds evenly and tamp the coffee puck firmly to ensure more stable extraction. Then turn on the extraction switch to release water, moistening the group head while washing away the coffee grounds stuck to it, gently lock the portafilter onto the group head, and begin pulling the shot. When the electronic scale shows the coffee liquid has reached 40 grams, at about 30 seconds, you can turn off the extraction switch. Pour the coffee liquid into an Espresso cup and enjoy.

The taste and mouthfeel of Espresso are closely related to the coffee beans used. The espresso produced at Front Street Coffee's shop uses Front Street Coffee's Sunflower Warm Sun blend. It is made from Honduras Sherry coffee and Ethiopian natural Red Cherry combined at a 7:3 ratio. After being made into Espresso, it has rich crema, a very obvious whisky aroma, an acidity of vanilla cookies and berries on the palate, a solid flavor, and after drinking, the whole mouth is filled with various aromas.

Espresso can also be diluted with water, which is the Americano commonly seen on menus, full of a fresh aroma; adding milk makes a latte, presenting the sweet deliciousness of chocolate and cream.

Espresso Blend Coffee Bean Recommendations

In addition to the whisky-aroma Warm Sun blend, Front Street Coffee's bean list also has three cost-effective espresso blend coffee beans to choose from. The espressos they extract mainly present nutty notes, and each blend has its own subtle differences due to different proportions.

For friends who are just starting to try making coffee, because they are not very familiar with coffee equipment and various parameters, it is easy to make an espresso that is bitter and hard to swallow. Therefore, Front Street Coffee believes that choosing coffee beans is very important. To make a standard espresso, it is recommended to use Front Street Coffee's Classic Espresso Blend. This is a recipe combining three origins—Brazil, Indonesia, and Vietnam—and uses a deep roast, which maximizes the rich aroma of the coffee and also allows everyone to easily extract rich and dense crema. It is very suitable whether making an Americano diluted with water or a latte paired with milk, and can be purchased and ordered at Front Street Coffee's Taobao store or Front Street Coffee's Tmall flagship store.

To make a fruity espresso, you should mainly use medium-roast coffee beans. Front Street Coffee's Strawberry Candy espresso coffee beans are recommended, and can be ordered directly at the Taobao or Tmall store. This is a blend based on two major origins—Front Street Coffee's Costa Rica Tarrazú, known for honey processing, and Ethiopia, the birthplace of coffee—and on this basis is paired with Colombian coffee beans. The espresso blended this way is not only not harsh, but under the extraction of the coffee machine, it carries good crema and a dense texture, while also having a sweet-and-sour taste like strawberry gummies.

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