Although we rarely take the initiative to drink espresso in daily life, if we want to make various popular drinks, such as American style, latte, and cappuccino, we cannot do without a cup of qualified espresso as the base. So this article will tell you how to make good espresso.
What are the characteristics of an espresso machine?
Espresso is a percolation method that uses a precision metal filter. Compared with hand drip extraction, the biggest difference is the pressurization. The high pressure in the espresso machine penetrates the water through the coffee powder, which means that even though the coffee powder itself is extremely fine, it can still ensure moderate percolation and balanced extraction. The finer the coffee grounds, the more surface area they increase at an exponential rate, so one advantage of very fine grounds is that extraction is extremely fast. Not only is it faster, but the quality is better. High pressure can squeeze water into the inner cell walls of coffee powder, allowing it to release rich oils and aromatic flavor substances.
When we brew coffee in any way, the goal is to release the positive flavor substances in the coffee through water, thereby obtaining delicious coffee liquid. Coffee beans are composed of various substances, 30% of which are soluble in water, such as fruit acid, caffeine, oils, carbohydrates, etc. Only about 20% of the aromatic small molecules with positive taste will be released first; the remaining macromolecules with woody and bitter taste will take longer to be extracted. Therefore, the barista’s job is to adjust the corresponding parameters to extract more high-quality ingredients in the coffee.
Espresso represents coffee with a complex and condensed flavor. No other brewing method can produce such a body and texture. If you want to get a cup of delicious coffee, excellent extraction is essential, and the aromatic compounds and taste compounds of the coffee in the cup are balanced. To put it simply, the sour, sweet, and bitter tastes must make people feel comfortable. Therefore, it is necessary to judge the state of the espresso by tasting it, and then decide how to adjust it to make a qualified concentrate.
In terms of operation, there are many factors that affect the flavor of a coffee bean to a cup of espresso, including grinding size, coffee machine boiler pressure, water temperature, powder filling pressure, powder amount, extraction time, extraction liquid weight and other factors and details. Normally, the pressure and water temperature of the coffee machine are set and cannot be changed easily. The powder distribution and filling pressure will be controlled according to the barista's habits. The four major factors used to adjust extraction in daily life are powder volume, time, liquid weight, and grinding degree. As the saying goes, “It’s hard to make a meal without rice.” For delicious food, the raw materials must be selected well, so the quality of coffee beans is very important.
What coffee beans are used for espresso?
Because espresso is extracted under fine grinding, high water temperature, and high pressure, espresso brings together a variety of flavors, and various flavor compounds impact our tongues exponentially. Therefore, if we use lightly roasted single-origin coffee beans for extraction, the taste may be too strong and mask the aroma of the coffee. As a crop, coffee will change with the climate, soil, etc. Even if it comes from the same place, the flavor of each batch of coffee beans will be different. The blending of coffee beans uses the method of complementing each other's strengths to ensure that every coffee bean can show a balanced and stable aroma and taste.
Front Street recommends Front Street’s home-roasted "Sunflower Warm Sun Blend Coffee Beans", which is made from Ethiopian sun-dried red cherry coffee beans (30%) + Honduran sherry barrel coffee beans (70%). The espresso coffee has flavors of sherry, vanilla, and cream, combined with the tropical fruits and fermentation of red cherries, giving the coffee in the cup a rich and soft taste. The aroma that comes out after swallowing is unforgettable. Whether it's an Americano diluted with water or a latte with milk, it has a rich aroma and taste.
The surface of a freshly made espresso coffee is covered with a thick, dense layer of golden foam, called crema. This is the result of the carbon dioxide produced by freshly roasted coffee beans being foamed under high pressure in the coffee machine. In order for everyone to drink the full aroma of coffee and enjoy the most complete tasting stage, Front Street only ships freshly roasted coffee beans within 5 days.
Espresso making steps
The daily espresso coffee produced at the Front Street store uses the "Sunflower Warm Sun Blend". FrontStreet Coffee (FrontStreet Coffee) baristas adjust the espresso extraction parameters before opening the door every day before officially starting production.
Front Street uses a double powder bowl capacity, and the amount of powder is about 18 to 20 grams. When Front Street produces coffee, 20 grams of coffee powder is used. The extraction ratio of Front Street is 1:2, that is, 20 grams of coffee powder extracts 40 grams of coffee liquid. The time is related to the flow rate of the coffee powder. Generally, the duration of a single extraction is controlled between 20 and 35 seconds, because within 20 seconds, the coffee tastes easy to be thin, and if it exceeds 35 seconds, it is easy to over-extract and produce a burnt and bitter taste. Most of the concentrates in the front end are in the range of 28 to 30 seconds.
Before extraction, you need to dry the powder bowl first, turn on the grinder, grind out a double amount of coffee powder, place it on the electronic scale and increase or decrease it to reach a weight of 20 grams. Then use a powder spreader to spread the coffee powder, and press the powder press vertically downward to fill the coffee powder cake tightly to ensure more stable coffee extraction.
Then turn on the extraction switch and let in water for 1 to 2 seconds to moisten the brewing head and take away the coffee grounds stuck on it. Place an electronic scale under the cup where the Espresso is connected, return the weight to 0, and place it under the brewing head during extraction.
Gently snap the handle onto the brewing head and start turning down the extraction switch. Observe the changes in the extraction liquid. When the electronic scale shows that 40 grams of coffee liquid has been extracted, and the time is about 30 seconds, pull down the extraction switch. The brewing parameters will change subtly based on the daily air humidity and the state of the coffee beans, so the amount of coffee powder, scale, and extraction amount of coffee liquid need to be adjusted up or down.
The extracted Espresso can be drank directly, and gargled with a glass of water. You can taste the dense oil foam and the mellow taste of the underlying coffee liquid. If you cannot accept the strong bitter taste, you can also add water and milk according to your preference to dilute and soften the strong taste.
Suggestions for adjusting parameters for making espresso
When we brew coffee on a daily basis, the adjustment of coffee extraction needs to be discussed based on experience, especially when we make it at home and the cup volume is small. Small changes in various factors can easily affect the taste of the final concentrate. Front Street recommends that you record more parameters in order to summarize and adjust. For example, the Front Street store needs to be debugged every day before opening, and various parameters are within the preset range, so there is no need to make major adjustments. Instead, we directly taste the flavor of espresso to judge the extraction status and then fine-tune the above parameters.
If the espresso has negative flavors such as burnt and bitter under the same extraction ratio, but the concentration is moderate, it may be that the time is too long, resulting in the extraction of a burnt and bitter taste. The general solution is to adjust the grinding degree to be coarser. When the espresso tastes weak and has a low concentration, it may be that the flow rate is too fast or the amount of powder is too small, resulting in insufficient extraction. You can increase the extraction concentration by adding more powder or adjusting the grind size. The above parameters are constantly changing with the extraction state. We need to pay more attention to the adjustment direction brought by the extraction variables in order to better grasp the high-quality flavor of the coffee in the cup.
Professional coffee knowledge exchange. For more coffee bean information, please follow Coffee Workshop (WeChat public account cafe_style)
For more specialty coffee beans, please add FrontStreet Coffee on private WeChat, WeChat ID: qjcoffeex
You can now buy the above coffee beans online at the Taobao store “FrontStreet Coffee” (前街咖啡). FrontStreet Coffee is a long-established specialty coffee roaster in Guangzhou, China, and its Guangzhou retail shop sells coffee beans only. The shop carries dozens of coffee beans from different origins around the world, including carefully selected single-origin beans for V60 pour-over and espresso. Guangzhou’s FrontStreet Coffee shop is recommended by many coffee lovers.
The FrontStreet 2013 Yunnan coffee beans sold in the store come from the Typica variety grown at FrontStreet Coffee’s own plantation in Yunnan. The name comes from the year the brand and the plantation were founded. You can buy these beans from China’s Yunnan origin at the Guangzhou shop and at FrontStreet’s Taobao store.
FrontStreet coffee beans are freshly roasted within 5 days and deliver consistently excellent quality and great value. Orders placed before 17:00 are shipped the same day, and most areas within Guangdong Province receive them the next day.
FrontStreet Coffee Taobao store: https://qianjiecoffee.taobao.com
Or search for “前街咖啡” (FrontStreet Coffee) on Taobao
Important Notice: FrontStreet Coffee has moved to a new address: 315, Donghua East Road, Guangzhou (coffee beans only)
Tel: 020 38364473
