Distributing the coffee grounds is a crucial step in making espresso, directly affecting the extraction results and flavor expression. This article will systematically explain the purpose of distribution, common misconceptions, and correct operating methods from Front Street's perspective. By understanding the flow characteristics of water through the coffee puck and mastering techniques to avoid channeling, it helps coffee enthusiasts improve extraction uniformity and craft a balanced cup of espresso.

Distribution refers to the process of manually loading the ground coffee into the portafilter basket and spreading it evenly within the basket. It is a key step that cannot be overlooked in making quality espresso, and the quality of distribution often directly determines the final performance of a cup of coffee. Today, Front Street will focus on the topic of distribution and explain how to achieve ideal ground coffee layer distribution.

Although distribution may seem like a simple step, it hides many details that are easily overlooked, and these details precisely influence the extraction results, thereby changing the flavor direction of the coffee.

Distribution

Ultimately, whether it is distribution or tamping, the shared core goal of both is to avoid channeling. Water is naturally inert and always tends to flow toward the area of least resistance. When coffee grounds are unevenly distributed in the portafilter basket, a large number of "channels" form between the particles, and during extraction hot water will concentrate through these channels, causing part of the coffee grounds in the puck to be over-extracted while another part is severely under-extracted. The final taste is both sharply acidic and bitterly burnt, making it hard to accept.

Therefore, the first thing we need to do well is "distribution." After a measured dose of coffee grounds enters the portafilter basket, its distribution must be readjusted so that the coffee layer is as even as possible throughout the basket. In this way, the tamped puck will not leave channels that allow hot water to "take shortcuts."

However, most people are accustomed to directly catching the coffee grounds falling from the grinder with the portafilter, which causes the grounds to pile up in the center into a "little hill," or creates an uneven left-right distribution. Facing these two states, Front Street does not recommend directly using a distribution tool to distribute the grounds.

The reason is that when the distribution tool is pressed downward, it creates a downward force, and this force first compacts the grounds piled up in the middle, after which the distribution tool spreads out the uncompacted grounds on the surface.

In this situation, the surface of the puck appears level, but in reality the coffee dose is concentrated in the center while the surrounding area is extremely sparse. A puck in this state is very likely to develop channeling during extraction; not only are there many gaps, but it also significantly affects espresso extraction.

To emphasize again, water is inert and will flow in the direction that is easy to pass through. Even if we have already distributed the grounds evenly and completed tamping, water still has a path that is easy to pass through, and that is "the edge of the puck," namely the area where the coffee grounds contact the portafilter basket.

Although the puck looks tightly and densely compressed, because the surface of the portafilter basket is smooth and level, the puck and the basket wall are not completely fitted together. Under pressure as high as 9 bar, water will preferentially rush into these gaps and then penetrate into the central area to extract the coffee grounds. This also explains why, when espresso flows out, the coffee liquid always converges from the surroundings toward the center.

Without using a dosing funnel, the coffee grounds caught in the portafilter basket often show a distribution with some areas concentrated and some areas sparse. At this point, you cannot directly distribute the grounds, because the use of a distribution tool applies a certain amount of pressure, creating an effect similar to tamping. The correct approach is to first gently stir the coffee grounds with your finger, moving the excess piled-up grounds toward the areas with too little coffee.

Next, gently tap the portafilter basket from the side, allowing the coffee grounds in the basket to naturally fall into their proper "positions."

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