Basic principles of hand brewed coffee extraction? How do you make it? Water flow and quantity, how to extract?

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The basic principle of extraction of hand-brewed coffee? How do you cook it? What's so particular about water flow and water volume and how to extract it?

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 based on 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. The special substances in the coffee beans are dissolved by hot water, and the coffee grounds are filtered and removed. 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.

After writing the French press, the actual operation of "dipping" has basically come to an end, leaving only the cold soaking pot, and I intend to combine the cold soaking pot with iced coffee and introduce it later. Starting from this article, the "practical operation" series will begin to talk about "filtering".

Filtration is divided into pressure filtration and drip filtration, both of which have one thing in common and one difference. What they have in common is that, except for minor adjustments, it is basically difficult to change the contact time between the powder and the water; the difference is that the force that forces the water to pass through the coffee powder and filter material, the pressure filtration comes from the pump or vapor pressure, while the drip filtration depends only on gravity. The representative equipment of pressure filtration is Espresso coffee machine and mocha pot, and there are many kinds of dripping equipment, such as hand filter cup, flannelette filter bag, Chemex glass filter pot, electric filter pot, Naboliao, Vietnamese coffee filter cup and so on.