The familiar coffee bean is the seed of a fruit produced by plants of the genus Coffea. This small, round fruit is commonly referred to as a coffee cherry due to its visual resemblance to a true cherry.
The Botanical Classification of Coffee
The coffee cherry is classified as a drupe, a fruit characterized by a fleshy exterior and a hardened shell surrounding the seed. Other drupes include peaches, olives, and true cherries. The coffee plant belongs to the Coffea genus, part of the Rubiaceae family.
The coffee cherry is composed of several layers protecting the seeds. The outermost layer is the skin (exocarp), which turns deep red or yellow when ripe. Beneath the skin is the mesocarp, a thin layer of sugary pulp. Encasing the two seeds is the endocarp, a paper-like protective shell known as parchment.
Inside the parchment are the two coffee seeds, which are typically covered by a thin membrane called the silverskin. The coffee “bean” is correctly identified as the seed, containing the embryo of the new plant.
From Cherry to Bean
The transformation from fleshy fruit to dry seed requires processing to remove the fruit layers and expose the bean. This separation dictates the flavor profile and is accomplished through two primary methods: wet processing and dry processing.
Wet processing (the washed method) involves removing the skin and pulp using a mechanical depulper shortly after harvest. The seeds are then fermented in water, which breaks down the sticky mucilage layer. Finally, the seeds are washed and dried, resulting in a cleaner, more acidic flavor profile.
In contrast, dry processing (the natural method) is the most traditional approach. The entire coffee cherry is spread out to dry in the sun for several weeks. The fruit layers dry onto the seed, allowing the bean to absorb natural sugars and fruity notes from the pulp. The dried outer layers are then mechanically hulled to expose the green seed.
Uses for the Fruit Flesh
The discarded fruit material (skin and pulp) is a substantial byproduct of coffee production, often amounting to millions of tons annually. Traditionally, this pulp was treated as waste or returned to the fields as compost.
There is a growing movement to utilize this material for its unique properties. The dried skin and pulp are known as cascara, Spanish for “husk” or “peel.” Cascara is used to brew a herbal tea (tisane), offering a flavor profile reminiscent of hibiscus and dried fruit.
Utilizing cascara provides an additional revenue stream for farmers and addresses the environmental challenge of managing organic waste generated during processing.