How does the caking of coffee powder affect the effect of humidity on coffee extraction? is the coffee powder coarse or fine in rainy days?

Guide reading

With the continuous drizzle in recent days, Guangzhou has officially ushered in spring. Recently, a small friend said in a private message, "how to adjust Italian products in rainy days?" So this issue of baristas will tell you how to deal with Qianjie, hoping to help you.

What will be the effect of rainy days?

Some friends who do not understand but think this is very powerful may think that sunny and rainy days are not very common, so why should we specifically talk about the adjustment of Italian products on rainy days? On the other hand, the baristas who suffer from it have a lot of experience. The direct impact of rainy days is the increase in humidity in the air. Qianjie measured today that the indoor relative humidity is 78%, which belongs to a high humidity level.

Humidity

Humidity mainly affects the extraction of Italian coffee in two aspects. The first one is coffee beans / coffee powder. We know that coffee beans are stored in a cool and dry environment, so it is easy to get wet in such a high humidity indoor environment. Therefore, Qianjie suggests that the coffee beans in the bean barn should be collected and sealed in the coffee bag, especially when closing at night.

And sometimes we will grind the coffee powder when we produce it, and after each grinding, the coffee powder will remain in the powder bin or on the channel from the knife head to the powder outlet. These ground coffee powders are easily disturbed by water vapor, such as caking, loss of flavor and so on. And if you don't clean up the powder, it will become the next cup of concentrated coffee powder. This is also a main reason why the subsequent production of espresso is unstable after we have debugged the espresso.

The second point is that in general, the higher the humidity, the lower the air pressure. The pressurization of the Italian coffee machine to 9bar is adjusted under normal atmospheric pressure, if the normal atmospheric pressure is less than 1, then the fixed pressure of the coffee machine will be less than 9bar. This is also the reason for the sudden change in the weather and the instability of Italian products.

So how to adjust the Italian production in Qianjie?

First of all, make sure that coffee beans are not exposed to too much moisture. The practice of Qianjie is to put the coffee beans in the bean warehouse into the coffee bag when closing at night, and wash the oil and water in the bean warehouse, and usually empty the residual powder in the bean warehouse to avoid affecting the next cup of espresso.

When debugging espresso every morning, first check whether the bean grinder is clean, and then put in the coffee beans. And use yesterday's grinding scale and extraction parameters for extraction, yesterday's grinding scale is 2, extraction parameters is 18.5 grams extraction 35 grams of coffee liquid, the time is 28 seconds, while today's test actual extraction time is 22 seconds, the flow rate is obviously accelerated.

Note: due to high humidity, coffee powder is easy to agglomerate, so cloth powder is particularly important, uneven cloth powder is easy to appear channel effect or local density is too high, the flow rate is too slow.

Then debug the grinding degree for the second extraction, Italian grinding in the case of similar extraction results suggest a small lattice small adjustment, this time fine a small grid, that is, 1.9 (fine adjustment is moving the dial under the operation of the machine to avoid the occurrence of jagging), the time after extraction is 25 seconds, the taste is slightly thin and the flavor is not complete.

Then continue to fine-tune a small frame (scale 1.8) to test for 27 seconds. It tastes good to try. So the stability of the parameter was tested twice, and it was found that the flow rate in the back section of the second cup extraction was on the high side, and the time was 25 seconds. By observing the pressed powder, it was judged that the smaller volume of pressed powder was caused by the finer grinding, which caused the tumbling phenomenon on the surface of pressed powder. So choose to increase the amount of powder to 19 grams. After confirming the extraction for many times, we worked out today's extraction plan, with a scale of 1.8 and 19 grams of coffee powder to extract 35 grams of coffee solution for 28 seconds.

Even after debugging the espresso in the morning, it does not mean that it is suitable for the whole day. The degree of grinding should be adjusted appropriately according to the real situation to ensure the stability of the product.