Discussion on filter-paper hand-brewed coffee key points of filter-paper hand-brewed coffee

Discussion on filter paper hand-brewed coffee

Basic equipment for filter paper hand brewing coffee

Hand pot, filter cup, filter paper, coffee pot, thermometer, bean grinder, spoon, scale, coffee beans

Key tips for filter paper hand-brewed coffee

The ratio of powder to water is 1:17, the temperature is 900.95 degrees Celsius, the stable uniform extraction, the extraction rate is 18% 22%.

Phenomena and causes in the brewing process of filter paper hand-made coffee

1. The phenomenon of steaming: expanding into hills

When hot water is poured in, the gas in the coffee powder expands due to heating (when the coffee powder is enlarged, it will look like a honeycomb, with many gaps). After the gas expansion, it will begin to discharge the excess gas, which will cause the coffee powder and hot water to form an expanding hill on the outside (Note 1). At the same time, in addition to the discharge of gas from the inside of the coffee powder, hot water also slowly seeps into the inside of the coffee powder so that some soluble substances in the coffee powder begin to dissolve and form a high concentration of coffee liquid.

In the final stage of steaming, because the gas is almost discharged, the whole temperature decreases, and some undischarged air begins to shrink slightly, so from the outside, the hill will also become moist and slowly show a phenomenon of drying or slightly cracking and collapsing (figure 3), which also represents the completion of steaming and can begin a second water injection.

When injecting water for the second time, the high concentration of coffee liquid dissolved first during steaming will move to low concentration hot water. In the whole brewing process, due to the continuous pouring of hot water and the constant dripping of coffee, the concentration of coffee powder inside and outside will be different. This is also the reason why the coffee will be stronger at the beginning and lighter in the second half.

The factors affecting steaming include the water temperature, the amount of water, the length of steaming time and the storage time of coffee beans.