Processing method of washing coffee beans Clean coffee is not easy to come by

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Qianjie-Coffee washing process introduction

Wet processing

In 1740, the Dutch invented wet processing, the technological process, which includes harvesting → fresh fruit, flotation, → mechanical peeling, → fermentation, degumming, → washing, → drying (solarization or machine drying), → shelling and bean extraction.

Specifically, the picked fresh fruit is poured into the cleaning tank, the red fruit and the immature fruit are distinguished by flotation according to the density, and the peel and pulp of mature coffee fruit are removed by peeling machine. after peeling machine treatment, the coffee fruit will still have residual pectin, which is usually soaked and fermented in a cement-piled fermentation tank for 1-3 days (depending on the specific situation). The hydrolyzed pectin no longer sticks tightly to the coffee shell, and then rinses off with running water. Finally, the raw beans with shells are dried in the sun or machine to reduce the water content of the raw beans to 10%-12%, and then the peeling machine is used to remove the stiff pulp and shell, and the seeds of the coffee fruit-coffee beans-are selected by the wind.

The appearance of the washed coffee beans is clean, and the remaining outer silver skin is very little, showing a grayish green color. The appearance of sun-treated coffee beans is different from that of water-washed beans, so the silver skin of water-washed beans is less than that of sun-washed beans before baking. However, during the baking process, with the loss of moisture, the silver skin will fall off and be collected in the silver skin collector of the roaster (you can review the jump dry information | | roasting of perfect coffee (8)-there is an internal roadmap of the bean roaster. Please check it before pouring beans. Compared with the complete silver skin of sun-cured coffee beans falling off together during baking, the "inner silver skin" in the gap between water-washed beans does not fall off easily and remains in the center after baking. Therefore, during grinding, it will be found that the inner silver skin of washed beans is more than that of sun-dried beans.

The flavor of washed beans

Because the washed beans are dried after removing all the pectin, the biggest flavor feature is the bright and clean acidity! For example, citric acid, malic acid or irritating acetic acid have low viscosity, sweetness and game. The original market thought that the quality of washed coffee beans was better because there were few foreign bodies mixed into the coffee fruit after flotation, and the quality was stable and easy to control after removing all pectin. In addition, the refining process is time-consuming and the equipment cost is high, so the price is higher than that of natural drying coffee beans, which makes people feel high-end. But the water washing method requires a lot of water and produces a lot of sewage at the same time, for example, 50-100 kg of water is needed to produce 1 kg of raw beans.

Compared with the previously introduced flavor of sun beans, the flavor level of water-washed beans is also much less. With the increasing demand for flavor in the boutique coffee market, cleanliness is not the only goal pursued by washing. Producing countries no longer focus only on removing colloids, but increase the possibility of improving the quality of coffee during fermentation. For example, in recent years, some manors have developed the "double washing method". That is, the natural fermentation process is divided into two stages, and 80-90% of the colloid is removed after the first fermentation, and after cleaning, the second fermentation continues to remove the remaining colloid. Because there is not much colloid in the second fermentation, even if the fermentation time is prolonged, it does not produce a bad smell. In addition, pay more attention to the pH of water in the fermentation process, in order to control the fermentation process belongs to alcohol fermentation.

Knowledge: coffee beans are the fruits of coffee trees, which belong to perennial evergreen shrubs or small trees of Rubiaceae.

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