Espresso Brewing Methods | Espresso Extraction Practical Analysis | How to Adjust Grind and Tamping?

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A few days ago, we shared how to make a good espresso, and then we received a short video from a friend who asked some questions. We then discovered that many friends who make espresso don't know how to adjust according to the coffee extraction state! Today, let FrontStreet Coffee and everyone do a brief practical analysis to help everyone better extract espresso in practical applications.

First, let's look at the video uploaded to us by our netizen.

Let's first analyze the espresso extraction state in the video. For quite a long time after starting the extraction, the coffee liquid was "dripping" out, which can be considered as the grind being too fine, blocking the water from passing through. Additionally, upon inquiry, this friend used relatively fresh coffee beans. Strong coffee degassing + too fine grinding are exactly the reasons for the abnormal early extraction stage.

Then continue to analyze the state of the coffee liquid. In the middle stage of extraction, the left spout finally flows a water column, while the right side is still in a dripping state. Moreover, looking at the color difference of the coffee liquid flowing from both sides, especially the right side is very dark in color. This indicates unevenness inside the coffee puck. There are 2 reasons - 1: Uneven distribution, the coffee powder on the right half is more than the left half, resulting in higher density after compaction, causing uneven extraction on both sides; 2: Grinding problem, large clumps of powder are more distributed in the right half of the portafilter. The density of the powder clumps will be higher than that of loose coffee powder, causing some coffee to be under-extracted while some coffee is over-extracted, and the color of the flowing coffee liquid will be very uneven.

Then let's look at the coffee puck and portafilter pictures we asked to be taken.

Based on this coffee puck, we see that there is a lot of coffee powder on the edge, which may be residue left after not cleaning after tamping, or there is another possibility: your tamper and portafilter do not match. In addition, the puck indentation is very deep, indicating too much coffee powder.

Then look at the portafilter after removing the coffee puck. We have said before how to judge over-extraction problems. Like this, the residual coffee liquid in the portafilter is very dark in color, which means the over-extraction is very serious...

Finally, returning to the video, the 30-second video extraction is not over yet. The extraction time is too long, which is also a cause of over-extraction!

Through the above analysis, we can apply it to actual adjustments.

Dose Adjustment

To obtain stable output, a fixed dose is necessary. Otherwise, your coffee will be strong in one cup and weak in another. Moreover, if there is more than one barista at the bar, a fixed dose is the first element of your output consistency.

Each portafilter matched with a coffee machine will have a capacity standard. We generally weigh according to this standard. Whether it's too much or too little, it will extract an incorrect espresso, especially using too much dose, fine powder is easily sucked back into the shower screen, causing unnecessary damage to the machine~

Grind Adjustment

The powder particle state as shown above is not very normal. If such powder clumps appear on a quantitative automatic grinder, it is caused by static electricity. It's not a problem if you can easily poke them open with your fingers. But if it's due to too fine grinding, long-term uncleanness of the grinder burrs, or large agglomerates caused by wear of the grinder burrs, please check and rectify one by one according to the actual situation! Of course, the relationship of the beans will also be there. Using oily dark-roasted coffee beans, the problem of powder clumps is unavoidable.

The normal powder particle state should be as shown in the picture above. If we are using a grinder and coffee machine for the first time, we can first grind a little to observe: adjust the grind to be finer, then adjust to coarser while grinding, and you will find the change of powder particles from large clumps to small clumps to almost no clumps. Then generally speaking, a little small clump (due to static electricity) is a more suitable grind size. You can try to make a double shot first, and then adjust according to the time of 25±3 seconds, extraction amount = dose × 2. Finally, remember to taste and confirm the flavor!

Check Tamping

Why did we skip distribution? Because we have talked a lot about distribution before, and correct distribution does not mean correct tamping! This is a test of finger skill~ The following is only for ordinary tampers.

Our habit is to use 3 fingers (thumb, index finger, middle finger), 3 fixed points to "touch" to judge whether it's tamped flat. But if you are a novice, there is a good way to check whether the tamping is flat. Although it's relatively slow, it can intuitively judge and adjust~ Please see the picture below.

After tamping, hold the entire handle like this, and use 2 thumbs to touch and feel whether the entire tamper edge is parallel to the portafilter, then make fine adjustments according to the high and low places. Remember to only make fine adjustments for leveling, do not press down with your thumbs.

Finally, here's a normal extraction video. Everyone can pay attention to the time point when the coffee liquid first falls, the flow rate of both spouts, the end time, and the liquid weight~

Important Notice :

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