Espresso is a concentrated coffee beverage that Italians brew quickly under high temperature and high pressure using a pressurized coffee machine, with a golden foam floating on its surface. Each store's espresso tastes different because of the espresso beans and extraction recipe they use. Based on Front Street Coffee's actual production process, this article introduces in detail the dose of a double basket, the extraction ratio, time control, and steps such as distributing and tamping the grounds, and explains Espresso's two core characteristics—abundant Crema and extremely high concentration—to help coffee lovers fully understand the key points of making and tasting this cup of coffee.

Front Street uses the "Front Street Classic Espresso Blend" to make espresso. The baristas at Front Street Coffee (FrontStreet Coffee) first dial in the espresso extraction parameters before they officially begin serving.

Front Street uses a double basket capacity, with a dose of about 18–20 grams, and Front Street uses 20 grams of coffee grounds when serving. Front Street's extraction ratio is 1:2, meaning 20 grams of coffee grounds yield 40 grams of coffee liquid. The 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 tends to be thin, while over 35 seconds it is easy to over-extract and develop a burnt, bitter taste. Front Street's espresso mostly falls within the range of 28–30 seconds.

Before extraction, wipe the basket dry, turn on the grinder, grind the amount for a double shot of coffee grounds, and place it on a digital scale to add or remove until it reaches 20 grams. Then use a distribution tool to level the coffee grounds, and press the tamper vertically downward with force to tamp the coffee puck firmly, ensuring a more stable extraction.

Then turn on the extraction switch and let water run for 1–2 seconds to wet the brew head, which can also wash away the coffee grounds stuck on it. Place a digital scale under the cup that will catch the Espresso and tare it to 0, then place it together under the brew head during extraction.

Gently and slowly lock the portafilter onto the brew head, and start by flipping down the extraction switch. Observe the changes in the extracted liquid. When the digital scale shows 40 grams of coffee liquid extracted, at about 30 seconds, flip down the extraction switch. The brewing parameters will change subtly according to the daily air humidity and the condition of the coffee beans, so the dose of coffee grounds, the grind setting, and the extraction yield of coffee liquid need to be adjusted up or down.

The extracted Espresso can be drunk directly. Paired with a glass of water to rinse the mouth, you can taste the dense oil foam and the mellow, full-bodied coffee liquid underneath. If you cannot accept the intense bitterness, you can also add water or milk according to your preference to dilute it and soften the strong taste.

Main characteristics of espresso

Espresso, also called Espresso, is a coffee liquid that Italians extract quickly at high temperature using a pressurized coffee machine, with a layer of golden foam floating on the surface. Each store uses different espresso beans and different extraction recipes, so the flavor will vary, but a standard cup of espresso will have the following two characteristics.

Cream

When we order an espresso at a coffee shop and the barista brings it over right after extraction, we can see a thick layer of golden foam floating on top, which we call Cream.

Coffee beans produce a large amount of gas during roasting. Water dissolves out the carbon dioxide in them under high pressure, but as the brewed coffee liquid gradually returns to normal atmospheric pressure, the coffee liquid can no longer trap all the gas components, so countless small bubbles emerge from the liquid. These bubbles remain on the surface of the coffee liquid, looking like a stable layer of "bubbles." Rich and dense Cream means that the coffee beans used for the espresso were freshly roasted. Because the gas inside coffee beans is continuously released over time, the longer the time since the roast date, the lower the carbon dioxide content, and the smaller the foam layer during extraction.

If a cup of espresso has no Cream on top, it is very likely that the coffee beans were stored too long, or perhaps the espresso was made and left un-drunk for a long time, so the foam disappeared. The darker the color of the Cream, the richer the taste usually is. Because coffee beans undergo the Maillard reaction at high temperatures, the darker the roast of the coffee beans, the darker the color of the foam layer and the mellower the mouthfeel.

High concentration

The extraction of a single espresso needs to release a large amount of soluble substances in just a few dozen seconds, so the coffee grounds need to be ground very finely and evenly. After nearly boiling hot water and a high pressure of 9 atmospheres, the concentration of espresso is very high, all flavors are doubled and concentrated, and it presents a strong mouthfeel on the palate. After swallowing, various aromas remain in the mouth, with a lasting aftertaste. Therefore, many coffee shops serve a glass of water alongside a strong espresso for their customers.

A freshly made cup of espresso is covered with a thick, dense layer of golden foam on the surface, called crema. This is the result of carbon dioxide produced by freshly roasted coffee beans foaming under high pressure inside the coffee machine. To let everyone drink the full aroma of the coffee and enjoy the most complete flavor stage, Front Street only ships coffee beans freshly roasted within 5 days.

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