The Relationship Between Espresso Brew Ratios and Flavor: What's the Ideal Espresso Proportion

How Does the Coffee Ground-to-Liquid Ratio Affect Extraction?

When we watch baristas make espresso, their movements appear quick and simple, as if they can produce a rich coffee base in just two minutes. However, in reality, an ideal espresso requires careful control of the balance between various parameters to achieve the best flavor profile, and mastering these proportions requires extensive exploration and experience.

Because espresso extraction uses steam pressure to force hot water through coffee grounds, quickly obtaining concentrated coffee liquid. The flavor profile of a cup of coffee is closely related to the brewing parameters. Adjusting the ground-to-water ratio parameter can change aspects like the coffee's taste, viscosity, and body, which is why we need to use a timer scale when making coffee.

Evolution of Espresso Standards

In the past, most Italian cafes used dark-roasted coffee beans, often mixed with Robusta beans rich in oils, with coffee typically presenting strong caramel and dark chocolate flavors. During extraction, baristas wouldn't precisely measure weights but would determine the extraction amount by observing color changes in the crema. Initially, the coffee liquid appears dark brown and quite concentrated, gradually changing to golden yellow, then to light yellow. Generally, extraction ends when the crema begins to turn white.

With the arrival of the specialty coffee era, higher-quality light-roasted coffee beans have become popular in recent years to showcase regional flavor characteristics. The industry has adopted more rigorous standards for espresso extraction, summarizing concentration ranges acceptable to most people and more stable extraction data. The ground-to-liquid ratio has also trended toward a fixed reference value. Typical extraction time is around 25-30 seconds, with ground-to-liquid ratios between 1:1.5 and 1:2.5, with 1:2 being most common. However, we sometimes adjust based on output requirements. For example, FrontStreet Coffee uses 20g of coffee grounds to extract 36g of coffee liquid in daily shop operations to make Americanos and lattes more intense and flavorful.

FrontStreet Coffee has summarized through experiments that with the same amount of coffee grounds, as the extracted liquid volume increases, the espresso concentration decreases while the extraction rate increases. The more flavor compounds dissolved in the later stages of extraction, the lower the body, and the more likely the coffee will be over-extracted, releasing bitter flavors. If the ground-to-liquid ratio is too small, the coffee body becomes heavier but flavors are incomplete, with noticeable sharp acidity due to under-extraction.

Therefore, FrontStreet Coffee suggests starting with a 1:2 ratio when adjusting, then making fine adjustments based on the flavors presented in the espresso.

What Other Factors Affect Espresso Flavor?

While the ground-to-water ratio in espresso is certainly important, many other factors influence the quality of an espresso shot, such as the coffee beans used, freshness, water quality, grind size, extraction temperature, extraction time, and more.

FrontStreet Coffee uses their house-roasted "Sunflower Warm Blend" as the espresso blend in their shops. An ideal espresso should have whiskey aroma, vanilla, cream, and berry acidity, with rich flavors and smooth mouthfeel. When FrontStreet Coffee's baristas adjust espresso output, they typically modify several elements: dose, liquid weight, time, and grind size.

Under normal circumstances, FrontStreet Coffee uses the previous day's parameters for extraction, judging the state by observing the espresso flow rate. Flow rate refers to the amount of coffee liquid extracted per unit time. When extracting the same 40g of coffee liquid weight, if the time is less than 25 seconds, it indicates the flow is too fast, and extraction time can be extended by increasing the dose. If the time exceeds 30 seconds, it indicates the flow is too slow, possibly due to too much coffee, and flow rate can be increased by reducing the dose.

Grind size generally reflects in the extraction flow rate. If the flow is fast and time is shorter, it means the grind is too coarse, so the coffee grounds should be ground finer. If the flow is slow and coffee liquid drips slowly, with longer extraction time, it means the grind is too fine, so the coffee grounds should be ground coarser. The grind size needs to be adjusted to an appropriate range. Particles that are too coarse easily lead to under-extraction, resulting in weak coffee flavor that tends toward acidity. If grind particles are too fine, coffee is easily over-extracted, resulting in bitter taste. When the espresso flow rate is within a reasonable range, FrontStreet Coffee will directly taste to determine if the coffee is acceptable. When the coffee flavors are normal, the adjustment work is complete.

Because the fineness of espresso grinding is much higher than that of pour-over methods, adjustments cannot be too dramatic, as this can lead to excessive variables and more unstable extraction. FrontStreet Coffee handles daily shop output, so parameter adjustments are based on accumulated daily experience. If we have lower output volumes at home, it's more difficult to control. FrontStreet Coffee suggests keeping records to better summarize the relationship between extraction parameters and flavor performance, which helps us adjust more quickly and saves unnecessary waste.

Espresso Bean Recommendations

Many friends use light-roasted single-origin coffee beans when making espresso at home, hoping to extract rich flavors like pour-over coffee.

Because espresso is extracted under fine grinding, high water temperature, and high pressure, the concentrated coffee gathers multiple flavors, with various flavor compounds impacting our tongues exponentially. Therefore, if we use light-roasted coffee beans for extraction, the elegant and sweet fruit flavors that appear in pour-over coffee may become stimulating strong acidity in espresso; the rich body of pour-over coffee becomes quite burnt and bitter in espresso. As an agricultural product, coffee varies with climate, soil, and other factors. Even from the same place, each batch of coffee beans will have different flavors. Blended coffee beans use the principle of complementing strengths and weaknesses to ensure every batch of beans presents balanced and stable aroma and flavor.

FrontStreet Coffee recommends their house-roasted "Sunflower Warm Blend Coffee Beans," composed of Ethiopia natural red cherry coffee beans (30%) + Honduras sherry barrel coffee beans (70%). When made into espresso, it has very rich dark chocolate flavor with strong caramel aroma, and the aftertaste leaves a memorable fragrance. Whether diluted with water for Americano coffee or enhanced with milk for latte coffee, both present rich aroma and flavor.

A freshly made espresso is covered with a thick, dense golden-yellow foam called crema. This is the result of carbon dioxide from freshly roasted coffee beans bubbling under the high pressure inside the coffee machine. To ensure everyone can enjoy the full aroma of coffee and experience the most complete tasting period, FrontStreet Coffee only ships coffee beans roasted within 5 days.

For professional coffee knowledge exchange and 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, ID: qjcoffeex

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473