For more knowledge about specialty coffee, please follow the WeChat public account: Front Street Coffee (FrontStreet Coffee）
Italy is a country of coffee culture, and espresso, which has spread around the world, is the soul of coffee and a treasure that Italy has given to the world. As the name suggests, espresso is a type of coffee that takes a short time to make, a short time to drink, and a strong flavor. This is a cup of pure concentrated coffee essence.
Making espresso is not simple because there are many parameters that need to be calibrated. Such as coffee grinding size, water temperature, extraction time, extraction ratio, etc., these are the keys to the quality of espresso coffee. The extraction ratio is another parameter that requires precision. Today Front Street will share with you the extraction ratio of espresso and learn the secret behind the ratio.
Powder to liquid ratio
In fact, there is no completely fixed parameter for the extraction ratio, and it needs to be adjusted according to the situation. However, there are unwritten regulations in various industries, that is, they will be based on the most prestigious ones in the industry as a common value to form a benchmark in the industry. For regular espresso, the extraction ratio is controlled between 1:1.5 and 1:2.5. The Front Street store uses a ratio of 1:2.
The extraction ratio includes the amount of powder and the weight of the extracted coffee liquid. In China, the extraction ratio of single and double coffee is based on the amount of the handle powder bowl equipped with the coffee machine. The single coffee is between 8-9g and the double coffee is between 18-20g. The single coffee coffee extraction ratio is 28-30 and the double coffee 30-40g espresso liquid is extracted within 25-30 seconds. The Front Street store coffee machine is equipped with a double powder bowl with a capacity of 20 grams. When producing, 20 grams of powder will be used to extract 40g of coffee liquid, and then adjusted up or down according to the concentrated extraction state of the day.
The increase or decrease in the amount of powder can change the firmness of the coffee powder cake, thereby determining the flow rate of the concentrate. The firmer the powder cake will be, the slower the flow rate of the coffee liquid will be, and the longer it will take to extract the same amount of coffee liquid, the corresponding coffee liquid will be thicker and the extraction rate will be higher. Normally, you need to decide how to increase or decrease the amount based on the flow rate and flavor judgment.
Grinding degree
In most cases, a cup of espresso can be extracted in just a few dozen seconds. In such a short extraction time, to fully extract the aroma of coffee, the coffee powder needs to be ground finer and evenly, which means a special electric grinder is needed for espresso extraction and grinding.
Because espresso amplifies the flavor of coffee, the grinding requirements are very strict. The thickness of the grind is difficult to judge with the naked eye, and is generally reflected in the flow rate and flavor of the espresso. If the grinding degree is too coarse, the coffee powder particles will be larger, the powder cake will be looser, and the time for water to pass through the coffee powder will be shorter, which will lead to insufficient extraction and the coffee flavor will be weak and sour. If the grind particles are too fine, the coffee will be easily over-extracted, resulting in a bitter and sharp taste. In addition, since the fineness of Italian grinding is much higher than that of manual grinding, the adjustment cannot be too drastic, which can easily lead to excessive variables and more unstable extraction.
How to adjust extraction parameters
The extraction of espresso coffee changes with the air humidity and the state of the coffee beans under the influence of weather. For example, rainy days will be more humid than sunny days, and coffee powder will easily absorb more water, thus affecting subsequent extraction. When we extract espresso coffee, the water temperature and pressure rarely change easily, and are usually set at a fixed parameter. For example, the coffee machine in the Front Street store uses 9 Bar and a water temperature of 94 degrees Celsius. Generally, the coffee in the cup is adjusted by adjusting the three parameters of grinding degree, powder volume, and coffee liquid weight.
For example, the extraction parameters used by Front Street the day before were: 19.8 grams of coffee powder, 38 grams of coffee liquid, and 29 seconds. Extraction was carried out according to the same amount of powder, and the liquid weight of espresso was 38 grams, but the time changed to 26 seconds, indicating that the flow rate became faster.
At this time, Front Street will first change the flow rate by increasing the amount of powder by 0.1 grams each time. Front Street uses 20 grams of coffee powder and extracts the same liquid weight, and the time becomes 29 seconds. When tasting the concentrated coffee liquid, there is no strange bitterness, but the aroma is slightly flat, indicating that the coffee is not extracted enough. It means that the effect of increasing the amount of powder is not obvious enough. It is necessary to change the grinding degree. Here, it is necessary to finer the particles to make the particles smaller and fully release the flavor substances. On the contrary, if the flow rate becomes slow, you need to speed up the flow rate by reducing the amount of powder first. If reducing the powder fails to achieve the effect, adjust the coarse grinding degree. The direction of parameter adjustment is flexible. As long as we are familiar with the characteristics of coffee beans and coffee machines, it is not difficult to quickly debug delicious Italian coffee.
In addition, the extraction of espresso is also related to the roasting degree of the coffee beans. The lighter the roasting degree, the harder the coffee beans are, and the poorer the water absorption effect of ground coffee powder. It is easy to cause perforation and splashing during extraction, and the coffee flavor will be insufficiently extracted. For this reason, if you want the espresso to be extracted stably, Front Street Coffee recommends giving priority to medium roasted, medium dark roasted, and dark roasted coffee beans. Front Street below lists several Italian blended coffee beans according to different tastes. You can choose and buy according to your preferences and needs:
"Front Street Blend 100% Arabica Coffee Beans" 75 yuan/454g: Colombian washed coffee beans + Brazilian semi-dried coffee beans, with flavors of nuts, dark chocolate, and caramel.
"Front Street Classic Blend Coffee Beans" 33 yuan/100g; Brazilian semi-sun-dried coffee beans + Indonesian Mandheling coffee beans + Vietnamese coffee beans, with rich coffee oil and mellow taste;
"Front Street Strawberry Candy Espresso" 43 yuan/100g; Costa Rican coffee beans + Panama coffee beans + Ethiopian coffee beans. It has the aroma of roses, strawberry candy and glucose. The sweet and sour fruit is prominent and has a pleasant taste.
After adjustments, a normal cup of espresso coffee is produced here on Front Street. You can refer to it. Front Street uses its own roasted "Front Street Sunflower Warm Sun Blend Coffee Beans", which is a blend of 30% Yirgacheffe sun-dried and Honduras.
Front Street will use 20 grams of coffee powder, and extract 40 grams of coffee liquid under a pressure of 9 bar according to a powder-to-liquid ratio of 1:2, and the time will be controlled in 30 seconds.
The flavor of espresso is rich in vanilla and cocoa, with the sour aroma of berries. As the temperature drops slightly, the flavor of cream begins to emerge, with a dark chocolate aftertaste. The overall taste is uniform and the taste is rich and smooth.
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
