Espresso Brewing Process Considerations: Extraction Techniques and Tamping Pressure Standards

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Want to make a perfect espresso? The steps aren't complicated, but many coffee enthusiasts find that after pressing the extraction button, either the flow rate is completely abnormal, or the taste is simply "unbearable."明明别人也用这款咖啡豆，研磨度、粉量、时间、比例，连动作也都学习到位了，怎么就做不出教程里面漂亮的Espresso呢？

As the saying goes, details determine success or failure. We all know that espresso is the fastest-brewed fresh-ground coffee, with the machine extracting the essence from coffee beans in just tens of seconds. To achieve a delicious espresso, not only must every parameter be carefully considered, but the operational details must also be treated with precision.

Today, FrontStreet Coffee will share those seemingly insignificant details that can gradually affect your espresso quality. Let's see if you've encountered these common mistakes before~

1. Using a wet portafilter to receive coffee grounds

Rinsing the portafilter with water to remove residual coffee grounds from the previous shot is a standard procedure for all baristas. Before the next extraction, the water should be wiped off to maintain a dry state.

However, some people get "lazy" and directly use a wet portafilter to receive coffee grounds. At this point, some of the first falling powder will be moistened and form clumps. Subsequent distribution and tamping have minimal effect on these water-absorbed coffee grounds, resulting in very unstable espresso flow rates during extraction—sometimes fast, sometimes slow. Naturally, the extracted espresso won't be very good.

2. Tamping directly without proper distribution

Simply put, the purpose of distribution is to ensure coffee particles are evenly spread in the portafilter, allowing hot water to "fairly" penetrate each particle, thereby maintaining consistent extraction.

But some people start tamping with the tamper before "leveling" the coffee bed, creating a small depression on the surface. During actual extraction, this seemingly insignificant depression provides an opportunity for water to exploit, causing channeling and spraying. Additionally, using a wet tamper can stick to and remove small amounts of coffee grounds, leaving the puck surface uneven. For this, FrontStreet Coffee suggests allowing the fluffy powder to settle as evenly as possible after dosing before tamping, and gently tapping with your hand when necessary.

3. Repeatedly tamping the coffee puck

Besides uneven distribution, tamping details also affect the final extraction. Some people pursue extreme perfection, repeatedly tamping back and forth.明明已经填压过一次，当看到有一边高出了点点，就往那边再压一下。Although the coffee layer may appear flat after multiple tamps, the internal density has actually been altered, making channeling more likely during extraction.

In reality, there's no need to be overly meticulous about the puck's flatness. As long as it's not obviously uneven, it won't significantly affect coffee extraction. When tamping, try to do it in one go. If you can't achieve evenness in one tamp, it indicates incorrect posture or force application—practice your technique again. Modifying the puck through secondary pressure will cause layering.

4. Accidental collision of the portafilter before extraction

According to FrontStreet Coffee's observations, people with this issue usually have larger movements. When inserting the portafilter, they're particularly confident, not finding the right angle before pushing up, thus hitting the group head. At this point, the originally compacted puck has likely "shattered," greatly increasing the possibility of channeling. This phenomenon is not only common in home brewing but also a frequent bad habit among novice baristas.

5. Forgetting to flush water before attaching the portafilter

If there's a long interval between the current espresso extraction and the previous one, the temperature of the shower screen in the group head will be very high. If you don't flush some water to cool it down first, attaching the portafilter might scorch the surface of the coffee puck. This can result in extracted espresso with burnt and bitter flavors. To avoid the impact of residual grounds, FrontStreet Coffee recommends developing the habit of flushing some water before attaching the portafilter.

6. Delaying extraction after attaching the portafilter

Some people, after tamping, can't find a place to put the portafilter and attach it to the group head early, then prepare the cup, digital scale, and position everything before starting the extraction. Coffee extracted this way often develops a burnt, bitter taste.

Due to the high temperature of the group head, once the portafilter is attached, if you don't press the extraction button to release water, the puck will be baked by the high temperature, releasing burnt and bitter flavors. Therefore, after firmly attaching the portafilter, you should immediately start the extraction to avoid over-extraction and waste.

In addition to the small details listed above, FrontStreet Coffee believes it's necessary to mention tamping pressure, which is also a concern for many beginners.

The purpose of tamping is to reinforce the connection between coffee grounds, preventing hot water from easily breaking through the coffee powder and affecting extraction. Therefore, we only need to ensure that the downward pressure applied is uniform and appropriate! Many people struggle with proper tamping largely due to incorrect posture (as shown in the picture below), such as non-vertical arms or uneven force application. This can be easily improved—as long as we practice diligently, we can master the true essence of tamping!

The most common tamping technique involves the thumb and index finger each holding one side of the tamper, with the remaining three fingers and palm wrapping around the handle, arms vertical, applying downward pressure.

But as FrontStreet Coffee mentioned, this technique truly requires continuous practice to grasp its essence. So if you don't want to spend money on equipment, constant practice is the best choice! When we can properly execute distribution and tamping movements, we can more easily make delicious espresso!

Important Notice :

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