厭氧日曬 Anaerobic Natural
最近流行的厭氧日曬 ，是將整顆咖啡櫻桃先作厭氧發酵 、再作日曬處理。咖啡生豆的處理過程都有發酵作用，發酵是一種自然變化，咖啡櫻桃中同時有糖和水分，即發酵所需二個基本要素，在有氧或無氧條件下，分解有機物，改變咖啡的風味。
The recent popular anaerobic natural method is to anaerobic ferment the whole coffee cherry first, and then leaves it for natural sun dry. The process of green coffee beans has the effect of fermentation. Fermentation is a natural change. There are sugar and water in coffee cherries at the same time, which are the two basic elements required for fermentation. Under aerobic or anaerobic conditions, organic matter is decomposed and the flavor of coffee is changed.
Basically, the anaerobic process makes the coffee more even and easy to monitor. The aerobic process is more complex and harder to monitor. In an anaerobic environment, the decomposition rate of pectin and sugar is slowed down, and the pH value also decreases at a slower rate, prolonging the fermentation time, thereby developing a better sweetness and a more balanced flavor. The temperature controlled by anaerobic fermentation must be lower than 10-15°C. In a closed and clean stainless steel fermentation vessel, the coffee beans are fermented for three days without oxygen. Then put it on tray for sun drying.
Injecting carbon dioxide into a closed container and squeezing out the oxygen inside, in this anaerobic environment, the decomposition rate of sugar in coffee pectin is slowed down, and the pH value also decreases at a slower rate, prolonging the fermentation time, thereby developing a better sweetness, and a more balanced flavor.
這種處理法所製作的咖啡豆有著更飽滿的醇厚度，明亮的酒香，低酸，較佳的甜度.（The result is a more full-bodied, slightly winey, sweeter coffee with less acidity.）
Fermentation in a closed environment can reduce the uncontrollable factors of the external environment on the fermentation process. Prolonged fermentation in an oxygen-free environment adds a full flavor and avoids uncomfortable dryness and sourness. The result is a more full-bodied, slightly winey, sweeter coffee with less acidity.