The core process of the extraction principle is as follows: 1 grind coffee beans and increase the surface area of coffee in contact with water

When it comes to "brewing" coffee, there are many kinds of coffee making equipment and different methods on the market. But in terms of the principle of coffee extraction, it's all the same.

The core process of the extraction principle is: (1) grind coffee beans to increase the surface area of coffee in contact with water; (2) fully soak coffee powder in aqueous solution and hydrophilically dissolve coffee essence; (3) separate coffee solution and coffee grounds.

All modern coffee extraction is the two core processes of soaking and filtration, which belongs to the category of physics, and there is basically no chemical change in the process. The differences in the thickness of coffee powder, the length of soaking time, the method of separation and filtration, and so on, have created a wealth of coffee brewing utensils and techniques. Although the core process of coffee extraction is the same, according to the significant differences in pressure and time used in coffee extraction, modern coffee extraction methods can be simply divided into two types:

1: Italian Fast espresso (Espresso)

It was invented in Italy and extracted 30 milliliters of espresso in 22s-27s seconds at 9 atmospheric pressure, 88 °C and 95 °C water temperature. This is significantly different from other coffee extraction methods, which can be done under unnatural conditions, reflecting the intervention of science and technology. Espresso Espresso can generally be made by Italian semi-automatic coffee machine and full-automatic coffee machine. A good Espresso requires higher price and quality of coffee machine and bean grinder.

2: immersion extraction (Steep Extraction)

It is a traditional, natural and simple way of coffee extraction; the extraction temperature is close to 85-92 and the filtration pressure is about 1 atmospheric pressure. It can be subdivided into:

Pressure filtration:

Use artificial pressure to filter coffee, including French pressure (French coffee cup French Press), AeroPress

Siphon:

Use the pressure difference caused by steam cooling to filter coffee, including siphon coffee maker Syphon, Belgian coffee maker

Drip filtration:

Natural gravity drip filter coffee, including American electric drip filter coffee maker, Vietnamese drip filter coffee maker, Swiss gold Swissgold kf-300 drip filter coffee maker, hand filter module, ice drip coffee maker, etc.

Steam pressurization:

Italian mocha pot Moka, many manufacturers also claim that mocha pots can make Espresso for commercial interests, but the coffee made by early mocha pots is essentially different from modern Espresso coffee. The pressure of mocha pots is only more than 1: 00 atmospheric pressure, and the pressure and final coffee extraction time may not be as fast as siphon coffee pots. According to performance indicators, we still classify mocha pots as natural traditional soaking extraction Steep Extraction.