Can I pour the coffee powder back and grind it a little more? What does secondary grinding mean in hand-brewed coffee?

As we all know, we determine the grinding degree and the water temperature during brewing based on the characteristics of coffee beans, in order to be able to rush out the beans with the most perfect performance. But occasionally, we will inevitably forget to adjust the scale of the bean grinder when grinding coffee beans, for example, using a coarse grinder to grind a coffee bean that needs to be finely ground.

This leads to the fact that the coffee powder lacks a certain extraction efficiency because the particles are too thick. If it is directly put into brewing, there is a high probability that the coffee will become less delicious due to the reduction of extraction efficiency (relatively speaking). So, some friends would think: "Can we put this coffee powder into the bean grinder again and grind it again with the correct scale, so that it can be ground to the size we need? "

Of course! Qianjie often shares that in world-class coffee competitions, players often use secondary grinding to grind coffee powder. The purpose is very simple, that is, to increase the uniformity of the particles. However, this method still has two less than pleasing flaws. If we cannot overcome such flaws, Qianjie still recommends that you use another method to "directly cook" the incorrectly ground coffee powder, so that it is easier to make an ideal cup of delicious coffee. Too much fine powder: As we all know, ground coffee powder usually carries a certain amount of fine powder, that is, particles with a powder diameter less than 0.25 mm. The proper presence of these fine powders can add a certain sense of layer to the coffee, but if the amount is too large, it will easily cause clogging, resulting in excessive coffee extraction and obvious miscellaneous flavors. Secondary grinding will lead to a further increase in the proportion of fine powder. Because the number of times coffee powder is ground increases, the amount of fine powder will naturally increase accordingly. (On the right is the second-ground coffee powder. You can clearly see that there are many fine powders clustered together.)

If the quality of your bean grinder is not so outstanding and the amount of fine powder will be more, Qianjie will recommend that you sift out some of the fine powder through a powder sifter after using secondary grinding, which can effectively reduce the number of overturns caused by excessive fine powder (such as clogging, excessive extraction, etc.).

The problem of "eating" powder: The second problem is the problem of eating powder! We all know that most electric mills will "eat" powder! Because there will be a certain gap around the grinding area of the bean grinder, this will cause some coffee powder to fall out after grinding because it falls in a certain corner of these areas, and ultimately the amount of coffee powder we get will be less than the amount of coffee beans put into grinding. For example, when you throw in 15 grams of beans, only 14.7 grams of powder comes out. This is what we often call the bean grinder "eating" powder.

And if we put in coffee powder, the amount of powder eaten by the bean grinder will further increase! Moreover, this number will be much more than everyone imagined! Qianjie has conducted several such experiments, which is to put coffee powder back into the bean grinder for secondary grinding. The final results were without exception. Only about 13g of nearly 20g of coffee powder could be successfully separated from the bean grinder, and the remaining few grams of powder were left in the bean grinder due to static electricity or falling in a dead corner. Then we need to "wash" the powder left in the coffee maker by "washing" it with beans or blowing it with air. (Detailed drawing of the interior of the bean grinder)

If you use a hand grinder or have a tool such as an air blower that blows coffee powder out of the bean grinder, you can still try a second grinding. But if there are none, try adjusting the parameters to directly brew the coffee powder later! Because even if you use coarsely ground coffee powder, you can also make a delicious cup of coffee through reasonable parameter matching.

Cooking and sharing is easy! Although the originally set extraction efficiency has been reduced due to the rough grinding of the coffee powder, we only need to increase the values of other parameters and adjust the water injection method to make up for the missing extraction efficiency, and then rush out. A cup of delicious coffee!

Water temperature and time are parameters that can be adjusted in addition to grinding. The Qianjie Association here recommends that you correct the extraction efficiency by increasing the water temperature, because it is simpler and more intuitive to increase the water temperature than extending the time. So this time, Qianjie will use the new one recently published on Taobao Tmall store-Qianjie Panamanian Alida Anaerobic Sun-cured Kaduai for sharing. The grinding will be coarser by two squares on the original basis. The extraction parameters are as follows: powder amount used: 15g powder to water ratio: 1:15 Grinding degree: 10.5 scale of Ek43, 70% sieving rate of No. 20 screen (Regular brewing: 9.5 scale of Ek43, 75%~80% sieving rate of No. 20 sieve) Water temperature: 94°C (Regular brewing: 92°C) Filter cup: V60 Extraction time: 2 minutes The brewing method is also three-stage. First, we use twice the amount of water to steam for 30 seconds.

After the steaming was completed, we began to inject the second section of hot water, a total of 120ml. It should be noted that because the grinding of the coffee powder becomes thicker, the drainage speed is increased, so if we want the coffee extraction time to be less than 2 minutes, then we cannot inject water in the original way. Otherwise, the gap between the flour and the flour will be too large, causing the water to be discharged too quickly, allowing the coffee to be extracted early, and eventually insufficient extraction will occur. This is also the reason why Qianjie does not recommend that you adjust the time. In this case, we can appropriately reduce the water flow, which can effectively extend the extraction time. Inject the second section of hot water in a large circle with a small water flow, and then wait until the second section of hot water has almost penetrated before starting to inject the third section of hot water.

Similarly, the third section of hot water is also injected using a small water stream, with a total of 75ml, but the scope of the circle has changed from the original large circle to the size of a coin. After filling, just wait for all the hot water in the filter cup to drip out before removing the filter cup and ending the extraction. The total time is 2 minutes. The Qianjie Alida anaerobic sun-cured kaduai prepared with this method and parameters is no different from the one prepared with conventional parameters. They all have a balanced taste, smooth taste and long finish. The flavors of berry, cream, apricot and other fruits are all outstanding, which is very good!

Qianjie here just gives you an example, so that when you encounter a similar emergency before brewing, you can use this idea to adjust the parameters, so that you can make an equally delicious cup of coffee ~

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