When it comes to espresso, everyone's first reaction may be strong and bitter black coffee, which is also the most exciting drink. For baristas, adjusting the extraction of espresso can be said to be the most critical step every day, because all kinds of popular Italian coffee are inseparable from a small cup of espresso. Today Front Street will talk about what espresso is and the differences between various types of espresso.
What is espresso?
Espresso refers to coffee beans that are finely ground and properly powdered, using a semi-automatic or fully-automatic coffee machine, using high temperature and high pressure to extract coffee in a short time. According to the definition of espresso, an espresso needs to meet several conditions: sufficient pressure, water temperature, appropriate amount of powder, fine grinding and short extraction time.
What makes espresso different from coffee made in other ways (hand brewing, cold brewing, etc.) is the golden dense foam on the surface, which is Crema. Because the coffee beans are filled with gas after being freshly roasted, they are soaked in high-temperature hot water and subjected to high pressure during the extraction process. Gas will be squeezed out of the surface of the cell wall due to thermal expansion and contraction. The coffee extracted with hot water also contains some fatty substances, which allow the coffee liquid to cover the squeezed out gas through emulsification, thus producing dense bubbles. Crema is composed of vegetable oil, protein, sugar and some aromatic substances, so the freshly extracted espresso has a fragrant aroma.
Several types of espresso coffee
According to the Golden Cup Theory concept proposed by the European Specialty Coffee Association, when water contacts coffee powder, coffee releases about 30% of soluble substances, and the remaining 70% of the macromolecular wood structure cannot be dissolved. Among them, only 2/3 of the 30% are molecules with better flavor, so we need to adjust several key parameters to control the extraction rate to around 20%. According to the extraction method, espresso can be divided into three types: Ristretto (short extraction), Normale (normal) and Lungo (long extraction), all of which are espresso liquid extracted quickly using an espresso machine.
Ristretto Usually refers to Italian espresso, also called espresso. Compared with the common Espresso, Ristretto is relatively niche. The Flat White Australian white coffee we often see is made with Ristretto as the base. Ristretto means "limiting". We can understand it as "limiting" the amount of coffee extraction and only taking the first break of espresso, thereby increasing the concentration of the coffee.
For example, Front Street's Espressso extraction plan is to extract 40 grams of coffee liquid from 20 grams of coffee powder. The powder-to-liquid ratio is 1:2 and the time is 30 seconds. The extraction of Ristretto is to extract only 70% of Espresso, that is, 20 grams of coffee powder extracts 28 grams of coffee liquid, and the time will of course be shortened accordingly. In addition, you can also adjust the grinding degree of the coffee to slow down the flow rate and make the coffee liquid more concentrated. Since each coffee shop will make different adjustments according to the coffee beans used and the specific flavor and texture that the barista hopes to present.
NormaleIt is the most common and popular espresso. It is actually Espresso in the usual sense. Currently, most of the people on the market mainly produce Normale, but they will not put too much emphasis on it. According to Jinbei's standards, the extraction rate of Normale is between 18% and 22%, and the concentration range is 8% and 12%.
LungoIt is coffee made with twice the normal amount of water. "Lungo" means "long, extended" in Italian, and is also known as "elongated espresso," which means extending the extraction time, thus reducing the concentration of the coffee and making it taste softer.
After many adjustments and tastings, Front Street’s final extraction plan was to control Lungo’s powder-to-liquid ratio at 1:5. That is to say, 20 grams of coffee powder is used, the extraction time is extended to 42 seconds, and 100 grams of coffee liquid is extracted.
Things to note when extracting espresso
The golden crema floats on the upper layer of the coffee liquid. This is the result of the carbon dioxide and various gases in the fresh coffee beans being distributed in the water under high pressure. If you choose coffee beans that have been stored for too long (more than 2 months), you will not be able to extract Espresso with perfect oil. Therefore, Front Street recommends using freshly roasted coffee beans and raising the beans properly. The coffee beans shipped from Front Street will be confirmed to be freshly roasted within 5 days, so that they are still fresh when you receive them. Coffee beans need a period of exhaust after roasting. Since most Italian coffee beans are roasted medium to dark, such as the Sunflower Warm Sun blend coffee beans used in Front Street stores, it takes 7 to 10 days to emit carbon dioxide. Using well-raised coffee beans to make espresso not only has a full aroma, but the extraction will also be more stable.
There are thousands of parameter settings to extract a cup of delicious espresso. Front Street believes that the main control factors are several key factors: the amount of coffee powder, grinding thickness, temperature, extraction time, and extraction liquid weight. For example, when we drink espresso with a weak flavor and need to increase the extraction rate, we can increase the amount of powder, adjust the grinding size, and increase the water temperature. On the contrary, if the espresso is too bitter and bitter, we need to reduce the extraction rate, so we need to reduce the amount of powder, adjust the coarse grinding size, or increase the water temperature. No matter how you adjust it, the ultimate goal is to get a full-bodied espresso.
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
