How to Use an Espresso Machine! Key Considerations for Espresso Extraction! What Should You Pay Attention to When Extracting Espresso?

From grinding the beans to completing the extraction, making a shot of espresso takes less than 60 seconds. It might seem that brewing a delicious cup of coffee isn't a complicated operation. However, as FrontStreet Coffee often says, although it appears simple, there are actually quite a few details that require attention.

As the saying goes: "Details determine success or failure!" This principle is perfectly embodied in espresso extraction. Even if we find the optimal formula for extracting an exceptionally delicious espresso during early adjustments, if we overlook some details during the brewing process, then even when applying this formula, the resulting espresso will hardly taste good. Therefore, today FrontStreet Coffee will enumerate those details that affect coffee extraction during the espresso-making process! To consistently extract delicious espresso, we should pay attention to these details during preparation.

1. Hopper Pressure

First, before grinding coffee, we must check the amount of coffee beans remaining in the grinder's bean hopper, as this will affect the fineness of the ground coffee! For example, when the coffee beans in the hopper are less than one-quarter of the hopper's capacity, the quality of the ground coffee will decrease.

Because when coffee beans are being ground without the weight pressing down on them, they will bounce during the grinding process due to compression, resulting in less uniform ground coffee. This will cause the extracted espresso to deviate from the set parameters, with shortened extraction time and coffee prone to under-extraction. Therefore, if we want to achieve stable output, it's necessary to check the bean quantity in the hopper before grinding coffee beans. Generally, having the bean quantity occupy more than half of the hopper is sufficient. (If you don't want to load too many coffee beans, you can use other heavy objects to apply pressure instead)

2. Cleaning the Portafilter

Since many friends use portafilters rather than dosing cups to receive grounds, cleaning the portafilter will be the second detail to pay attention to (using a dosing cup would be the third). Because even if we rinse the portafilter promptly after extracting coffee, a small amount of coffee grounds might still remain stuck in the crevices; meanwhile, if our rinsing interval is not long, there will still be small water droplets remaining in the portafilter, which will also affect the stability of extraction.

If not cleaned, the presence of moisture will force part of the coffee grounds to be pre-moistened before extraction. When we then tamp it into a puck, the moistened portion of the coffee grounds will directly form channels, thereby affecting extraction; while the presence of coffee grounds, though not having as significant an impact, will still potentially cause effects. Therefore, before loading coffee grounds, we should wipe and clean the portafilter.

3. Observing the Coffee Grounds

After completing the above two steps, we can start grinding the coffee grounds. However, during the grinding process, there are also things we need to observe. One is the dispensing state, and the other is the coffee grounds themselves. The dispensing state mainly observes whether the coffee grounds, when being dispensed, come out in a wide range like the left image below, or in a concentrated small range like the right image.

Under normal circumstances, the dispensing state when grinding is like the right image, with concentrated dispensing in a small range. If we find that the dispensing state is like the left image, very widespread, it's highly likely that static electricity has caused some coffee grounds to clog at the dispensing outlet. Clogging will affect the quality of the coffee grounds we obtain, thereby causing deviations in extraction, so we need to determine whether the grinder needs to be unclogged through observation. (For detailed situations, you can refer to this article → "What to do when the grinder is clogged?")

Then another observation point is quite simple: check if the ground coffee has formed large clumps due to static electricity. If so, we should use a distribution needle or other needle-like objects to break them up, thereby reducing the occurrence of channeling effects.

4. Tamping

Next comes the distribution and tamping of the coffee grounds. These are two aspects that FrontStreet Coffee often emphasizes, because whether distribution and tamping are uniform will directly determine the stability of coffee extraction.

If we fail to achieve uniform distribution and apply even pressure during tamping, the coffee puck will promote the formation of channeling effects due to uneven distribution of coffee grounds and uneven heights. Since this point cannot be simply summarized in a few words, friends can refer to these two articles for understanding → "How to distribute and tamp correctly", "How much pressure should be used when tamping coffee grounds?". In summary, distribution and tamping are crucial for espresso extraction, so they deserve special attention.

5. Pre-flushing

FrontStreet Coffee recently shared the importance of "pre-flushing before espresso extraction". Before we lock the portafilter into the group head, we need to open the water valve once and flush hot water.

The purpose is simple: to remove residual debris on the shower screen again, while also making the hot water temperature for extraction more stable.

6. Avoiding Collisions

After completing all preparations, we can begin extraction. But there's one detail to pay attention to before extraction: try not to cause collisions with the portafilter. Many novice friends, unfamiliar with the structure of the coffee machine, often bump the portafilter when locking it onto the group head because they haven't aligned it properly with the notch.

The force generated by collisions will cause varying degrees of cracks in the coffee puck depending on the magnitude! For example, when the collision force is small, cracks mainly form between the puck and the portafilter basket, where the originally tightly connected areas separate due to impact, and these cracks become the main areas for hot water flow - huge channels; when the collision is more severe, the puck might crack directly, similarly, this will seriously affect extraction.

Therefore, if novices are unfamiliar with the locking position, FrontStreet Coffee suggests familiarizing yourself with the position beforehand before extracting espresso, otherwise bumps and collisions will easily affect the deliciousness of the coffee.

7. Delayed Extraction

Some friends don't extract immediately after locking the portafilter to the group head, but instead prioritize other tasks. This approach can easily lead to two problems with the extracted espresso: first, it will have obvious burnt bitterness, and second, the flavors won't be as full-bodied.

Because the shower screen in the group head maintains a constant high temperature, if the puck remains in contact with it for an extended period without extraction, it will continuously receive high heat, causing flavor compounds to deteriorate rapidly. If at this time we've loaded a larger amount of grounds, causing the coffee grounds to directly contact the shower screen, there's also a possibility of the puck burning, which will give the extracted espresso obvious burnt bitterness. Therefore, FrontStreet Coffee recommends extracting immediately after locking the portafilter to the group head, to avoid experiencing many undesirable sensations.

8. Prompt Cleaning

When we've completed the espresso extraction, remember to flush hot water again to clean the shower screen. This prevents the debris absorbed by the shower screen from being burnt, which would cause the next extraction of coffee to be "infected" with obvious burnt bitterness.

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