Introduction:Brewing a high-quality espresso shot involves more than just selecting the right coffee beans and grind settings — operational details are equally critical. This article delves into four common yet often overlooked extraction mistakes in the industry: not preheating the shower screen, failing to remove the puck promptly, neglecting to clean the shower screen, and leaving the portafilter locked in the group head for extended periods. It also provides practical recommendations and standard procedures from a team of professional baristas to help you improve the consistency and flavor performance of every shot of espresso.

During the espresso brewing process, many seemingly minor operational habits can have a profound impact on the final extraction results and coffee flavor. The following section details four common yet easily ignored extraction errors and offers professional and practical correct methods to help coffee professionals and enthusiasts establish a more standardized brewing procedure, ensuring the quality and consistency of every espresso shot.

First, a common yet impactful mistake is not running water through the group head to preheat and cool it down before locking the portafilter in place. Especially if some time has passed since the last extraction, the shower screen may have been exposed to the machine’s high temperature for an extended period, causing its surface temperature to become very high. If you then immediately lock in the portafilter filled with coffee grounds, the surface layer of the puck may scorch due to the sudden high heat, resulting in a noticeably burnt and bitter taste in the final espresso and severely compromising overall flavor.

To avoid this issue, it is recommended to first release some hot water from the group head before starting the actual extraction. This serves to lower the temperature of the shower screen while also preheating the portafilter, helping to stabilize brewing temperature and contributing to consistent flavor and smooth extraction.

The second common mistake is neglecting to remove the puck from the portafilter promptly after extraction, as many people get busy with making subsequent drinks such as lattes or Americanos. In reality, the puck remains hot and moist immediately after extraction. If left in the basket for too long, the moisture will gradually evaporate, causing the coffee grounds to stick firmly to the basket and shower screen. This not only makes subsequent cleaning more difficult but may also produce unpleasant burnt odors due to prolonged exposure to high heat.

More seriously, these dried puck residues may clog the bottom holes of the basket, leading to uneven water flow during future extractions and even potential damage to the basket structure. Therefore, it is advised to knock out the puck immediately after each extraction. This not only maintains equipment cleanliness but also helps extend the lifespan of your tools.

The third common oversight is failing to clean the shower screen promptly. Even small amounts of coffee grounds left behind can quickly dry under high temperatures, becoming harder to clean and potentially releasing off-flavors during subsequent extractions, which can affect the purity and flavor of the next cup of coffee.

The correct approach is to use the flowing hot water to briefly rinse the shower screen when removing the portafilter. This not only removes leftover coffee grounds but also keeps the shower screen clean and in optimal brewing condition, ensuring that every cup of coffee maintains a consistent standard of quality.

The last common mistake is habitually leaving the portafilter locked in the group head for extended periods, especially when not brewing. Doing so keeps the narrow space between the portafilter and group head at a high temperature, accelerating the aging of internal gaskets and potentially causing the coffee aroma to dissipate quickly due to sustained heat exposure.

Some users believe that keeping the portafilter locked in place helps maintain warmth and prevents the espresso from being too cool during extraction. However, a better practice is to open the group head and let water flow out just before brewing. This achieves the dual purpose of preheating the portafilter and performing a “water release for cooling,” replacing the habit of leaving the portafilter locked on the machine for long periods. This helps maintain equipment stability and ensures the best possible flavor expression of the coffee.

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