How to extract espresso? How do you make espresso? What is espresso?

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At the beginning of the 20th century, Italian engineers invented the steam espresso machine, and after several evolution, espresso became an almost unshakable position in the coffee world today.

From Espresso to Ristretto, from Cappuccino to Mochaccino, and the misunderstood Macchiato....

Espresso mainly uses high pressure to extract coffee liquid for a short time. There are many articles saying that it is a big fallacy to "make use of high temperature and high pressure". The extraction of coffee is about 85: 92, and if it is too high, it will easily have a bitter taste, which will not change because of high pressure. this is why the earliest invention of steam espresso has been improved. Because the water has to be converted into steam and heated to 100 degrees, the coffee is bitter and free of oil.

In terms of the fineness of coffee powder, in the world of espresso, the grinding scale can no longer be quantified by integers of 1, 2, 2, 3. The bean grinder that specializes in grinding espresso has no one-by-one turntable.

Like digital and analogy, if the turntable of one grid is digital espresso grinder is like analogy, maybe turning a little bit will be different.

In addition, it is worth mentioning that whether fresh beans are ground or whether they are freshly ground can be easily judged from the state of espresso, so whether the coffee is fresh and whether it is freshly ground and cooked is very important.

In the process of filling, the originally loose coffee powder will be compacted and tight, which means that the gap between the powder and the powder will be narrowed, the flow channel of water will become smaller, and the water will not pass easily, which means that the pressure can be maintained. But with the same channel size and the same flow rate, it may be "very fine powder + light packing" or "fine powder + heavy packing". Although the external flow rate is the same, the degree of extraction is very different.

Therefore, when adjusting the taste, the scale and filling pressure must be considered at the same time!

Generally speaking, the pressure of the coffee machine is about 8~9bar. As long as the pressed powder is not compacted enough to resist the pressure of 8~9bar, coffee can be extracted. In other words, it is possible that the coffee will not flow out.

As long as the powder is fine enough and the filling force is strong enough, it is possible. Be very careful at this time!

If the espresso doesn't flow out or drips slowly, be careful to squeeze your hand open under pressure, and you're likely to get scalded or drop the handle. Please pay special attention!

When filling and pressing, we should pay special attention to whether the surface of pressed powder is smooth and askew. Because high-pressure water will flow to places where it is easy to vent pressure, if the surface of pressed powder is not filled and pressed flat, it is easy to cause water not to flow evenly through the whole pressed powder and extract uneven, astringent and watery coffee.

Another way to decide to stop extraction is to rely on experience or look at color. Usually in the process of extraction, the color of crema becomes lighter and lighter. From the ochre red at the beginning to the yellowish brown later, if it turns into a white ivory color, you should stop as soon as possible, or even draw a cup.

There is a situation in which the flow rate is normal and beautiful at first, but suddenly the color changes quickly in the middle, even flowing like a faucet, then it is possible that a water hole has been created around the pressed powder, causing a large amount of water to pass through the hole, resulting in uneven extraction, which is best stopped as soon as possible. If you have already extracted half a cup, you can at least drink some, otherwise, you will only drink water and over-extracted coffee water.

The water hole may be caused by uneven filling, or it may be after the filling is completed, because there is a gap between pressed powder and the filter caused by knocking or other factors, high-pressure water will flow to a large gap, which should be paid attention to when filling.

The pressed powder knocked out is also very important. We can observe whether the extraction is uniform or not.

A few years ago, the espresso masterpiece proposed a model to separate the filter from the handle, fill the powder and press it, and then put it back into the handle for no more than one reason:

1. Easy to fill and press

two。 Handle and filter temperature

3. Cleaning is not easy

However, in fact, there are different opinions on these points, and the temperature is not reasonable. So use whatever method you like.