The principle of dissolving, extracting and filtering hand-brewed coffee explains how to make good hand-brewed coffee.

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What process does it take to bring the mellow coffee out of the coffee powder?

Dissolution, extraction and filtration

To know the coffee we are familiar with, we must first have an understanding of dissolution, extraction and filtration.

The principle of separating substances is to separate different pure substances from the mixture, and pure substances can often be separated by various physical methods with the help of the unique properties of various pure substances. Dissolution is the phenomenon that one substance (solute) is uniformly dispersed into another substance (solvent), while extraction is to separate the liquid components from the mixture by different solubility of the solvent. Dissolution is a phenomenon, while extraction is a mixture separation technique.

Junior high school teaching refers to the dissolution filtration method: using filter paper to separate the mixture of liquids and insoluble solids with different degrees of dissolution. The solid particles are large and cannot pass through the filter paper; the particles of water or solution are small and can pass through the small holes in the filter paper. Coffee is extracted and filtered. Use hot water to dissolve the special substances in the coffee powder, and then filter the coffee grounds. Generally speaking, the quality of coffee is affected by extraction temperature and filtration time. The higher the extraction temperature and the longer the extraction time, the more bitter the coffee.

When making coffee by hand, the filter cup is also one of the keys to affect the flavor. The shape, the number and size of the outlet hole affect the time of coffee liquid outflow. Some Japanese-style slow flushing techniques have only one hole, the flow rate is slow, and the coffee is rich.

To make a good hand-brewed coffee is to understand the state of dissolution, extraction and filtration of coffee powder, so as to select the most appropriate equilibrium state, but the extraction is not insufficient, and this process requires more practice and thinking, but, whether it is grinding degree, water temperature, brewing time or water injection method, it is nothing more than adjusting the extraction around the above theory, and the correct parameters are changing all the time. The wrong parameters are immutable.