The structure of mocha pot and how to use mocha pot correctly

Today, when Italian coffee is popular all over the world, we are no stranger to Italian coffee machine, and even passers-by can name several Italian fancy coffee. But today we have more criticism and discrimination against the mocha pot, and we always question whether the coffee made by mocha is Espresso. So Uncle Dou would like to share some of my views on the mocha pot.

Europeans do not call this kind of pot mocha pot, but call it Espresso Pot. Judging from this name, the coffee made by mocha pot is a veritable Espresso, only that its cup-making form is too classical and simple. Some friends questioned it because it was not as high-tech as the machine, and when it came out of the cup, it could not see the thick layer of fat in the cup, so they concluded that the coffee it made was not Espresso. But such doubts are unconvincing.

The structure of the mocha kettle

The mocha pot is divided into three parts: the upper seat, the powder trough, and the lower seat. The lower seat is a sink for holding water, and the powder trough is used to hold finely ground coffee powder. The upper seat is to hold the extracted coffee liquid.

If we first put the lower sink aside, fix the powder trough to the bottom of the upper seat of the mocha kettle by hand. We'll see more clearly how he was extracted.

First of all, the metal tube at the end of the powder trough is coaxial and the same diameter as the metal tube in the center of the upper seat, which is designed to make the water flow in a straight line. When the water in the lower seat reaches a certain temperature, driven by pressure, the hot water will be pressed up from the metal tube at the end of the powder trough, through the coffee powder in the powder trough, and then filtered through the filter at the bottom of the upper seat. under pressure, the coffee liquid overflowed from the metal tube in the center of the upper seat. In this way, the process of coffee extraction is finished in principle.

Let's take a look at the lower seat of this metal again.

Just from the safety valve above the lower seat, we can conclude that this pot is a container with pressure. When the powder trough is correctly and firmly screwed to the lower seat from the upper seat, it is set on the heat source to be heated, so that the hot water has pressure. So we say that the whole extraction process is completed under pressure. And Espresso, which means "to be under pressure..." in Latin. In other words, the method of boiling coffee with hot water and pressure extraction belongs to Espresso. Espresso is not only the name of this kind of coffee, but also the name of this kind of coffee extraction method.

Mocha pot is suitable for coffee and grinding fineness.

Let's first take a look at the basic requirement of Espresso Coffee, "want to get the coffee that is closest to the flavor of freshly ground coffee powder". From this alone, we can draw a line of thought on this question.

Roasted coffee beans

If we need to get strongger (stronger) taste, the process of coffee roasting is the most important. We all know that Dark (deep roasting) is more suitable for making Espresso, the reason is that with the deepening of coffee roasting, the greater the degree of expansion of coffee beans, the easier it is to extract more flavor substances in the later extraction process. But how deep it is depends on the baker's different understanding. Uncle bean will never roast coffee into the second explosion. Because I firmly believe that the coffee after entering the second explosion will not increase the intensity of the flavor, on the contrary, it will reduce the flavor of the coffee and increase the bitter taste of the coffee. "it's never the same thing to have a strong taste and a stronger bitter taste." Today we also see the baking degree of the internationally popular Espresso. There is even a tendency that the baking degree becomes shallow. This can be achieved from baking skills. It's not that if the coffee is lightly roasted, the thickness of the taste will not be enough, at least I don't think so. But for the broad audience, it is appropriate to choose coffee with a deeper roasting degree to make Espresso.

Grinding fineness:

Many friends also know that Espresso needs to fine grind the coffee powder in order to get more adequate extraction during the extraction process.

The production method of mocha pot (statement: the following production method is commonly used by Dou Shu)

1) inject hot water into the lower seat of the mocha pot, and the water level shall not exceed the lower edge of the safety valve. The safety valve is the limit of the maximum water level of each mocha kettle.

Uncle Dou does not recommend using cold water, which will increase the time it takes to soak coffee powder and make the extracted coffee bitter and turbid.

2) filter paper can be pasted at the bottom of the upper seat.

This is a form of modern mocha pot making method. Ten years ago, the mocha pot was made without filter paper.

When sticking the filter paper, the filter paper should be laid correctly in the middle of the lower seat filter. In order to achieve a better fixing effect, the filter paper can be soaked with water.

3) loading powder. This step is one of the important elements related to the cup effect of coffee (water volume, powder loading, extraction timing).

Many friends have made obvious mistakes in this step, which can be summarized as follows:

a. There is not enough powder. If you choose the highest water level in the lower seat, your powder should also be fully filled. Otherwise, with the lack of coffee powder, the taste of coffee will gradually fade.

b. Press the powder with a powder hammer. Many friends use the special powder hammer of Italian machine to press the powder trough of Mocha, which is a painstaking move. If the pressure is too tight and the coffee powder is too fine, the coffee will be difficult to draw. So the key to filling a mocha pot with real powder is to fill it as much as possible instead of pressing it tight. The powder can be injected in batches when loading the powder, and the edge of the powder trough can be covered as much as possible without leaving any gap.

When the coffee powder is full, tap the vertical table of the powder trough a few times to ensure that the coffee powder can be fully filled.

4) after correctly placing the powder trough on the lower seat, tighten the upper seat on the lower seat. You can twist it a little too much for safety.

5) heat the correctly installed mocha pot on the heat source. For ease of observation, I suggest boiling the mocha pot with the top open.

Soon the coffee liquid overflowed from the central metal column of the upper seat.

With the continuous extraction, the liquid level of coffee will rise gradually. When there is grease on the liquid surface, please be careful that the coffee extraction is coming to an end. When the color of the oil changes from dark to light, the heat source should be cut off immediately to stop the extraction, otherwise the coffee will be in a state of over-extraction.

In particular, you can't stop after the sound of "snoring". This kind of coffee may even have the taste of roasted rubber.

6) qualified friends can prepare a towel soaked in cold water in advance and put it next to the heat source. When you finish step 5, put the mocha pot on the cold towel. This will greatly reduce the possibility of over-extraction of coffee.

Tips

The maximum service life of the sealing ring under the upper seat of the mocha kettle shall not exceed one year, pay attention to replacement. It's kind of like the rubber seal of a pressure cooker. If it is not replaced in time, there will be lax sealing and air leakage.

If the phenomenon of gas outgassing or water leakage occurs in the lower seat pressure reducing valve during the manufacture of the mocha pot, the thin metal sheet in the middle of the pressure reducing valve should be replaced in time, otherwise the pressure of the mocha pot will be greatly lost.