In Coffee, what is a Wet Mill?
A wet mill, also known as a beneficio, factory, washing station, or receiving station, is a facility where whole coffee cherry fruit is brought for the initial stages of transformation into dried green, exportable coffee. It typically involves the use of water, although new ecological wet mills may use very little water. In traditional wet-processing, the wet mill is where coffee undergoes a series of steps. First, the coffee cherry is pulped to remove the outer fruit skin. Then, the coffee is floated in water to remove defective beans, fermented to break down the fruit mucilage layer, washed to remove the remaining fruit, and finally dried on a patio, screen, or mechanical dryer.
The wet mill plays a critical role in coffee processing, as it is where the quality and characteristics of the coffee can be greatly influenced. The wet mill can affect the coffee's flavor, aroma, body, and acidity, depending on the specific processing methods used. Factors such as the water source, fermentation time, and drying conditions can all impact the final product.
In recent years, there has been a movement towards more sustainable and ecological wet mills. These wet mills aim to reduce water usage, minimize waste, and utilize renewable energy sources. These eco-friendly wet mills can have a positive impact on the environment and can also produce unique and high-quality coffees.