Understand the wet treatment of coffee beans

There are two ways to prepare coffee beans for the baking process. The method chosen has a significant impact on the final price and quality of coffee. The cheapest method of processing is called "drying", which is used for lower-grade coffee beans, while higher-quality coffee beans are processed by "wet treatment".

The wet treatment process requires more capital investment and more energy, but this method helps to ensure the quality of coffee beans and reduce damage. The main difference between the dry and wet methods is: in the wet place

During the preparation process, the pulp is immediately separated from the coffee beans instead of drying them.

The pulp is separated in a separator-in a machine with a fixed surface and a movable surface, or in a machine with a movable rod, the fruit is crushed so that the pulp is separated from the coffee bean. In order to ensure the quality of coffee beans, the pulp must be separated as soon as possible after harvest, which is ideal within 12 hours, but not more than 24 hours. If the coffee beans are kept for too long, the pulp will become difficult to separate from the coffee beans, resulting in incomplete separation and possible damage to the coffee beans.

The peel and pulp separated from the coffee beans will be washed off with water. The flushing tank is designed to separate light and tender coffee beans from thick and ripe coffee beans. Such a separation can also be done by the Aagaard grader. Ogao, a coffee grower in Norway, designed a device to filter coffee beans into a large water container while growing coffee in Kenya. The large, full beans were the first to sink into the water, while the lighter ones stayed in the large container. In this process, water can be recycled.

The next step is the most basic fermentation, that is, the use of enzymes to separate the greasy glue that covers the inner pericarp. Coffee beans are stored in a fermentor for about 12 to 36 hours, which is mainly determined by the surrounding temperature, the thickness of the glue and the enzymes. When this process is completed, the endocarp around the coffee beans is no longer slippery but has a pebble-like feel.

Quality control is essential to prevent coffee tofu from rotting throughout the wet treatment, because even one rotten coffee bean can damage all coffee beans. For this reason, the equipment used must be cleaned every day to ensure that no impurities are left before the next round of processing.