What does the filter cup have to do with the filter paper? Why wet filter paper?

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What does the filter cup have to do with the filter paper? Why wet filter paper?

The reason for wetting filter paper with hot water is mostly due to the residual problem of bleaching fluorescent agent in white filter paper, if there is no such concern for unbleached pulp. On the premise of breathability, for example, in terms of steaming, the purpose is to make the coffee powder evenly absorb water particles after wetting, and then dissolve the coffee substance with the water rushed into the back hand, which can increase the extraction rate and concentration.

The influence of dried coffee powder under infiltrating or drying filter paper takes longer to brew coffee than the contact and absorption between filter paper and coffee powder, which means that whether the filter paper absorbs the smell of coffee or coffee powder absorbs the smell of filter paper does not seem to be so important and absolute. Because the extraction time is long, the taste will rush to the coffee pot below.

The air permeability caused by the design of the inner ribs of the filter cup is far greater than the problem of filter paper infiltration. Under the dry filter paper extraction, the coffee powder is soaked and steamed by hot water, and the filter paper is soaked by capillarity. Under the problem of CO2 discharge, although there is a difference of 2-3 seconds between the filter paper and the filter paper, the air permeability caused by the filter paper wall is the main reason.

Therefore, the design of the inner ribs of the filter cup, considering the diversion and ventilation, is to make the extracted coffee liquid flow smoothly. The spiral ribs of the traditional Kalita, Melitta, Hario conical filter cup, the column ribs under the KONO, the straight ribbed ribs with the field roast, the newly launched cake filter cup Kalita185 and the corresponding special filter paper (corrugated, tuzo and paper), the principle is the same, the filter cup and the filter paper position exchange only.

Considering the closeness between the filter paper and the filter cup, the top of the KONO filter cup is all smooth, gravity under full water will make the coffee liquid flow down, but the smooth surface around the top of the filter cup, the filter paper completely close leads to poor ventilation, causing the flow rate to be too slow and over-extraction, it is necessary to adjust the hand to slow down the water flow or segmented water injection to solve.

As for the problem of baking depth, the exhaust is poor during shallow roasting and brewing, the coffee powder particles are heavier and more silver, and the fine powder is easy to absorb water and block downwards, and the normal water column is not easy to drive the coffee powder layer to change, resulting in slow overextraction, which needs to be dealt with by continuous water flushing or a hand flushing pot with a larger water column and a more vertical flow of impact.