The reason why the handle of extracted coffee needs to be watered-hand coffee extraction time

The reason why the handle of extracted coffee needs to be watered-hand coffee extraction time

one。 Steaming:

When making hand-brewed coffee, most people pay a lot of attention to the softness of the current and the freshness of the coffee powder, and steaming is also indispensable. Good steaming can fully infiltrate the coffee powder, activate the coffee activity, and form a good gap between the coffee particles, thus making the coffee extraction process more smooth. The so-called activation is to make the coffee powder have a bulging state similar to a volcanic eruption. the coffee powder rises upward, the air between the coffee particles will be heated and expanded, and the coffee particles themselves will release a large amount of carbon dioxide. bubble-like voids are formed between the particles, which make the coffee powder form a uniform filter layer to provide the space needed for hot water to pass through.

The voids formed by good coffee steaming are approximately uniform, and the flow rate of coffee liquid filtered downward is also uniform. If a good filter layer can not be formed, then stagnant water will be formed, the drip filtration rate will be slowed down, the extraction time will be prolonged, and then the phenomenon of excessive extraction will be formed. Coffee taste will also be messy, sour-based, coffee itself is difficult to reflect, the taste is thin, with irritation, and the aroma is not dignified enough.

The best end time of steaming will be the sum of the surface tension of water and the pressure caused by carbon dioxide released by coffee powder when the expansion reaches the limit, which is slightly equal to the downward pulling force and stable water injection speed caused by the gravity acceleration of water and capillarity. at this time, the void layer in front of the coffee powder particles has not yet collapsed, so it is a good time to start the first water injection. Although a longer steaming time may give a thicker taste, it is also easy to affect the cooking results due to the increase of the surface area in contact with air and the rapid decrease of water temperature.

If you want coffee to have a lot of caffeine and thick coffee oil, while controlling the content of bitter substances, then the extraction time you need must be very accurate. If the time is not enough, the caffeine content is high enough, but the taste and aroma of the coffee will become monotonous and tasteless; if the time is too long, then you can only drink the bitterest coffee bar and the degree of grinding directly affects the extraction time. The finer the coffee powder, the larger the contact surface between the particles and water, which will lead to excessive extraction; if the coffee powder is too coarse, the contact area between the particles and water will be smaller, which will lead to insufficient extraction.

If you use high-quality coffee beans, but the coffee is not good enough, it means that the coffee powder is too coarse; if the coffee is too bitter, then it is possible that the coffee powder is too carefully ground. Water temperature can directly affect the integrity and speed of coffee extraction. The lower the water temperature, the longer the extraction time, so we can choose to use ice water to make coffee (ice droplets).

The content of caffeine in iced coffee does not change much, but its bitterness is much lighter than when brewed in hot water.

High temperature can make the extraction speed of coffee faster, and the extraction degree of organic components in coffee is more complete. But if the water temperature is too high, the grease will evaporate with the steam. Therefore, the coffee made from boiling water is very thin, but bitter and caffeinated.