The reason for the instability of espresso espresso extraction will the pressure in the bean warehouse of Italian bean grinder affect the flavor of coffee?

This situation is especially evident in busy coffee shops. In the morning, make all preparations, fill up the bean barn, and adjust the concentrated extraction plan for the day. As the amount of espresso extraction increases, then you will find that the flow rate of espresso is getting faster and faster. The time is several seconds less than the extraction scheme. Normally, the time error of a stable parameter will not exceed ±1 second.

In this case, the extracted espresso must be very different from the concentrated taste of this morning's debugging scheme. In order to stabilize the production, we must quickly adjust and grind the parameters to return to normal. There are many reasons for the instability of extraction parameters, such as the most error-prone barista operation problems, the parameter scheme itself is flawed and unstable, and the coffee machine has not been cleaned for a long time, but these reasons do not just make espresso extraction faster and faster. It is often accompanied by some obvious states, such as "channel effect". In fact, if you find that the average flow rate of espresso extraction is faster, and there is no "channel effect" and other problems, you only need to fill up the bean bin of the bean grinder. This involves an inconspicuous problem-soybean warehouse pressure. Let's take a look at a group of experiments on Qianjie with this question. Qianjie adjusts the parameters when the soybean warehouse is full, including the time setting of the quantitative bean grinder. The details are as follows:

The current scale of the bean grinder is set to 20g in 3.8 seconds. Through 5 consecutive pulverization, the error is ±0.2g. The extraction parameters are 20g coffee powder and 40g coffee solution, and the extraction time is 29 seconds.

Then the front street takes out the coffee beans in the warehouse, leaving only 1 stroke 4 of the height of the warehouse (the warehouse is designed to be wide and narrow, so there are actually fewer beans).

After 5 times of continuous pulverization, the powder extraction range of 3.8 seconds is 18.7-19.3g. That is to say, the quantitative error through time is quite large, fortunately, every time the product is produced, it will be weighed by a scale. if you usually only adjust the grinding degree in the morning, set the time, and the product within a day is no longer calibrated, the powder quantity may not be accurate.

Of course, this extraction still adds the coffee powder to 20g, through the test of 5 times extraction, the time is stable in 25-27 seconds. That is to say, when the parameters are constant, the extraction time of full warehouse is 2-4 seconds less than that of 1 stroke 4 warehouse. In other words, although the grinding scale has not changed, the actual coffee powder grinding thickness is slightly thicker. So when making espresso, don't wait for the beans in the bean warehouse to run out.