What should I do if the bean grinder gets stuck? What should I do if the Italian bean grinder doesn't produce powder? Espresso coffee blending logic!

"mixing concentration" is a workflow that makes every morning barista a headache. Because the difficulty of grinding does not depend entirely on the barista's experience, but also on the state of the beans and the influence of the weather. Even an old coffee veteran sometimes spends more than half a bag of beans on grinding for these reasons. So, it's something that depends a little bit on luck.

Today, when the weather is clear and the beans are in good condition (because they have been raised long enough), colleagues who have never thought of ploughing the coffee industry for many years have also sent a signal for help on the street. The reason is very simple, after adjusting the number of extraction, the coffee is still "go its own way", drink (not good)!

As described by colleagues, although it has been extracted many times and changed many times of grinding, there is almost no change in the extraction state and taste of coffee. After looking in front of the street, I immediately found a clue. Suddenly, the front street clairvoyant: maybe sometimes people can not adjust the concentration is really not bad beans, but because we overlooked an important factor, resulting in a lot of "useless work." (on how to adjust the concentration, Qianjie has been discussed in detail in the article "how to adjust the concentration quickly". Here is one of the major reasons why we will waste half a package of beans by mistake.)

What factors caused us to do "useless work"? The reason why we need to adjust the grinding when adjusting the concentration is that the extraction efficiency of the concentration is not up to standard, so we need to change the particle size of coffee powder through grinding adjustment, and then affect the extraction rate. Generally speaking, each adjustment of 1 scale will bring about a change in extraction time of about 3 seconds to 5 seconds. For example, the original time for us to extract 40ml liquid weight with 20g powder is 24 seconds, but after adjusting one frame, it will become 20g, and it will take 24 seconds to extract 40ml coffee liquid.

But if not, the 40ml coffee liquid is still extracted in 24 seconds, so it is necessary to observe the pulverizing state of the bean grinder. Because the grinding has been changed, but the flow rate has not changed, it means that the cutter head of the bean grinder has not changed with the adjustment. This probably means that the bean grinder is stuck. The cause of sticking powder is quite common, and that is the relationship of "static electricity". In the process of grinding, coffee powder will be easy to generate static electricity because of continuous friction, which will make coffee powder have adsorption. This adsorption force can not only make coffee powder and coffee powder adsorb and agglomerate each other, but also make coffee powder adsorb on other objects and affect it. The problem with the bean grinder like the above is that the coffee powder is adsorbed on the cutter head and outlet, causing a blockage to the bean grinder, thus affecting the grinding accuracy. Even if you change the grinding, the bean grinder will still grind you coffee powder of the same thickness. (inside the powder outlet of the bean grinder)

When coffee beans are roasted more deeply, ground more finely, and the grinding environment is drier, static electricity is more likely to be generated. Coincidentally, the Italian bean grinder has almost all the above three conditions: coffee beans are generally roasted in medium and deep depth; grinding is small particles close to flour; the bean grinder is usually placed next to the coffee machine, and the temperature of the coffee machine will reduce the humidity of the environment. It can be said that the Buff is all full. But even so, these conditions add up to caking coffee powder so that it doesn't get stuck in the bean grinder. Generally, there is only one reason for this situation, that is, when we empty the bean grinder and grind very few beans.

When we need to change the bean grinding, or need to adjust the grinding, we usually empty the bean mill. But at this time, there are always some remaining beans in the bean grinder that are difficult to clean up. I believe that many people will be the same as Qianjie, just grind them off directly. But it is precisely because of the grinding of these beans, which leads to the situation of stuck powder. Because these beans are not subjected to warehouse pressure during grinding, it leads to a lot of fine powder. And these fine powders are adsorbed everywhere because of static electricity, and when they are absorbed to the cutter head and powder outlet, they plug up naturally. And as said in front of the street, when this situation occurs, there is a very obvious phenomenon in the grinding of coffee powder, that is, "flying powder". Normally, the coffee powder we grind falls perpendicular to the center, while the flying powder caused by the card powder, literally, causes the coffee powder to fly out from different directions. The pulverizing range is very extensive (clogged state) ↓

Concentrated pulverizing range (normal state) ↓

Under lucky circumstances, the blockage is not so serious, we may be able to grind one more handful of beans to bring out the fine powder, and the grinding accuracy of the bean grinder will return to normal; if we are unlucky and the blockage is more serious, then even if we keep grinding, the bean grinder still maintains the original grinding degree. The solution is actually very simple and rough. All we have to do is take out a longer spoon (other slender sticks are fine) and use the handle to poke it from the powder mouth to the inside. Don't push, just gently knock down the powder adsorbed near the cutter head. Generally tinkering until there is no more fine powder, it basically means that the problem has been solved, the accuracy of the bean grinder has been restored, and we can start debugging as usual. (it is best to operate the bean grinder in a power-off or non-grindable state.)

Many friends ignore this point, which leads to the grinding cost of more than half of the bag of beans. Because no matter how to adjust, the bean grinder can not change the grinding degree because of the stuck powder, so naturally, it will not be able to adjust a good espresso. In addition to paying attention to whether the bean grinder is affected by the coffee powder with static electricity, we also need to pay attention to the fact that it is best to clean the knife head of the bean grinder regularly. Because it is not only static electricity, the oil produced by coffee beans will also cause coffee powder to absorb and clog, which will affect the grinding accuracy of the bean grinder. These cannot be pounded with long sticks alone, so setting a cycle and regular cleaning can appropriately prolong the service life of the bean grinder and its grinding accuracy.

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