What are the "immersion" and "filter" appliances in the most common coffee extraction methods?

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Qianjie Coffee talk about the most common methods of coffee extraction, there are no more than two ways: "soaking" and "filtering".

The former is more like the brewing method of tea, putting coffee powder and hot water in the container to ensure that the time and temperature is right and stop at the right time, while the "filter" is to let the hot water pass through the coffee powder freely.

The instruments that prefer "immersion" are: French kettle, smart cup, cold extract, siphon kettle, Turkish kettle.

The filters that tend to "filter" include: common hand filter cups, flannel, all Italian coffee makers, ice drip kettles.

This refers to "bias" because even in an extraction method, "immersion" and "filter" work at the same time, such as hand flushing with fine powder grinding and stirring, and the hot water stays in the filter for a period of time. The Turkish pot is more like a pure "immersion" appliance.

Next, let's take a look at the brewing method.

The first is gravity. Coffee is extracted by gravity, the degree of "diffusion" in the extraction process is moderate, and the degree of "erosion" is very low, such as Chemex, Hario V60 and other hand-flushing devices. Gravity can make the coffee taste more refined and more acidic.

When using the above equipment, be sure to keep the water temperature between 93 and 96 ℃ to ensure that the diffusion rate is high enough to extract soluble substances, especially acids, from coffee. This is especially important for hand-brewed coffee because acidity can increase the complexity and purity of the taste.

The second is stress. Such as Philadelphia and mocha pots. When coffee is extracted by pressure, the degree of "erosion" in the process of extraction is very high, and the degree of "diffusion" is medium to low. Stress can make the coffee taste thicker.

As the "diffusion" rate increases, more soluble substances and fibers in coffee will be extracted. Due to the higher rate, the time of coffee extraction needs to be adjusted accordingly. In addition, the type of filter can greatly affect the final taste of coffee.