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When it comes to brewing coffee, many people like to ask how many grams of coffee grounds to use and what the coffee-to-water ratio should be. Ultimately, what people really care about is the coffee extraction yield. It should be noted that 70% of the substances in coffee beans are insoluble in water, and even among the remaining 30%, only a small portion contains the desirable flavor compounds.

Compared with pour-over coffee, espresso has a more concentrated flavor, which means the defective flavors in the coffee beans are also maximized. This is also a characteristic of espresso. Therefore, if you want to drink a cup of latte or cappuccino with excellent flavor, in addition to using the right milk, a nearly perfectly extracted espresso as the base is also indispensable.

The Specialty Coffee Association of America (SCAA) once explained espresso this way: extract 45 ml of single espresso at 9-10 atmospheres of pressure, with 7-9 g of coffee grounds, at a water temperature of 88-92 °C, in 22-28 seconds. However, if you go to a specialty coffee shop and ask a barista about the espresso extraction parameters, you will find that the amount of coffee grounds used and the extraction yield are not exactly the same, and there is a huge divergence from the above standard explanation.

In Front Street's method of making espresso, an amount nearly matching the capacity of the filter basket is used, and the coffee-to-water ratio is closer to 1:2. However, such data is only for reference.

The roasting degree of coffee beans in the past and consumers' understanding of coffee flavor are already vastly different from today. People in the past preferred dark-roasted espresso beans and espresso with nutty and cocoa flavors, and even applauded burnt bitter flavors.

Nowadays, with the rise of the third wave of specialty coffee, people hope even more to taste floral and fruity aromas in coffee. The roasting degree used for coffee beans is lighter, and if the same water temperature is used, there will be a difference in taste. Espresso extraction parameters are now closer to: 18 g coffee grounds, extracting about 30 g of liquid weight, water temperature 92-94 °C, and extraction time falling within 25-27 seconds. It can be noted that the judgment has shifted from the volume of the coffee liquid to the more precise actual weight of the coffee liquid. The reason is that factors such as brewing pressure, roast level, and freshness affect the amount of crema, so judging by volume is very unreliable.

In recent years, coffee machine manufacturing technology has advanced by leaps and bounds. Coffee machines with variable pressure and emphasis on pressure profiling have been invented one after another, and brewing pressure is no longer fixed at 9 atmospheres. Whether it is the introduction of pre-infusion pressure or the gentle ramp out of pressure in the middle and later stages, various pressure curves that go beyond the old rules have been continuously experimented with and tested. Even for the same coffee bean, the flavor profile expressed under different pressure curves is different.

When Front Street makes espresso, it needs to consider factors such as grind size, extraction pressure, water temperature, dose, time, and extraction yield.

【Dose】Generally, the amount of coffee grounds used is determined by the capacity of the filter basket. For example, the filter basket used by Front Street has a capacity of 20 g, and Front Street will make slight adjustments under that amount, but not exceed the capacity. If there is too little coffee grounds, it is easy to underextract; if there is too much coffee grounds, the portafilter cannot be locked onto the group head.

【Water temperature】The higher the water temperature, the more substances in the coffee are extracted and the faster the extraction; the opposite is also true. The extraction water temperature for espresso is generally hot water that is about to boil.

【Time】The sour substances and bitter substances in coffee are the most obvious, and the sour substances are extracted faster than the bitter substances.

【Extraction pressure】In the early days of espresso making, the extraction pressure was extremely close to atmospheric pressure, and the extracted espresso had a thin mouthfeel with no crema in sight. With improvements in espresso machine manufacturing technology, starting with the appearance of the Faema E61, there began to be 9 bar of pressure and rich crema.

【Grind size】Grind size is the pain point of every barista, and air humidity also changes with different times. If the coffee grounds are too fine, the contact area between hot water and coffee particles increases, more substances are extracted, and over-extraction is likely to occur.

When producing espresso, Front Street adjusts the extraction parameters according to the day's temperature, humidity, and the roast date of the espresso beans, so as to extract a nearly perfect espresso. The extraction parameters are as follows:

Front Street espresso extraction parameters:

Grinder: Galileo Q18

Grind setting: 2.1

Coffee machine: Faema E98

Pressure: 9 bar±2

Temperature: 90.5~96°C

Time: 20~30 sec

Dose: 19.7 g (double espresso)

Extraction yield: 35 ml

After parameter adjustment, the espresso liquid extracted by Front Street Coffee (FrontStreet Coffee) shows a rich whiskey aroma, with rich flavors like vanilla and cream, berry acidity on the palate, a long black chocolate finish, and a viscous and smooth mouthfeel.

The reason it can have such a rich whiskey aroma is that the espresso beans used by Front Street Coffee (FrontStreet Coffee) stores are the carefully blended Sunflower Warm Sun Blend. This blended coffee bean is made from 70% Honduras Sherry and 30% Ethiopian natural Red Cherry.

Front Street Sunflower Warm Sun Blend coffee beans

Region: Honduras & Ethiopia

Varieties: Caturra, Catuai, Pacas, local heirloom varieties

Processing method: washed & natural

Seventy percent Honduras Sherry is carefully washed and then placed into Sherry whiskey barrels for low-temperature fermentation for dozens of days, allowing the whiskey aroma substances in the barrels to penetrate into the green coffee beans. Thirty percent Ethiopian natural Red Cherry brings the berry acidity unique to Ethiopia to this blend. The overall flavor of this blend is very appealing.

Some friends who have tasted the latte at Front Street Coffee (FrontStreet Coffee) find that Front Street's espresso has a rich whiskey aroma and cannot help wanting to drink the espresso straight to find out more. When Front Street serves espresso, it provides a small spoon and also serves a cup of ice water. Seeing this, friends may want to ask, why serve ice water, and what is the correct way to drink espresso?

Front Street will now explain the correctway to drink espresso. The purpose of the ice water is to let friends clean their palate before tasting the espresso, so as to better experience the flavor and mouthfeel. Before the coffee liquid enters the mouth, you can use the small spoon to check the condition of the crema or stir the entire cup of espresso so that the upper and lower layers of the coffee liquid are fully integrated, making the tactile sensation more balanced.

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