Natural and Honey Processing – An Overview

Sometimes called dry processing, naturally processed coffees don’t have anything to do with the adjective “natural” as we think of it in western marketing. Typically associated with organic or non-GMO foods at the supermarket, natural process coffee simply refers to letting the fruit dry out naturally – that is, without washing or mechanically stripping the fruit away. The majority of the world’s coffee (and nearly all its robusta) is dry processed. Though they have historically been thought of as lesser or lower quality than fully washed coffees, high scoring naturals are beginning to outsell washed coffees. Natural coffees are associated with bold fruit flavors, heavy syrupy bodies, and high sweetness.

 The process involved is much simpler than in fully washed coffees; simply put, fresh coffee cherries are spread out to dry on a patio or raised bed, where they stay until they are fully dried. Careful attention must be paid to avoid over-fermentation or molding. Practically speaking, this means coffees must be raked constantly – sometimes every fifteen minutes. Additionally, sometimes coffee is raked into piles and covered during midday, when the UV light is strongest and can cause damage. Coffees must also be covered and protected if it rains.

 Natural processing is the oldest method of processing – honey processing was developed in the 1990s. Honey processed coffees are treated much the same way – however they are de-pulped before drying. There is no actual honey involved, but de-pulped coffee that hasn’t been fermented is extremely sticky (hence the name). When honey process coffees are referred to with colors, it has to do with how much mucilage (fruit) was left on prior to drying (white – yellow – red – black). Pulped naturals are interchangeable with honey processed coffees; the difference lies only in the region. It’s usually referred to as pulped natural in Brazil and honey processed in Central America.

 We know that flora (yeasts, bacteria, and non-filamentous fungi) are much more involved during fermentation in naturally processed coffees – however, exactly how they act is less well known. It is a commonly held misnomer that naturally processed coffees have more sugar than washed coffees. Sugars do NOT pass from the fruit to the beans. However, it is true that brewed natural coffees have a higher perceived sweetness than fully washed, as well as more floral and fruity flavors. So, what’s going on here?

 While naturals don’t gain any sugars during processing, they DO have more sugar than washed coffees. When coffee is washed, it begins the germination process: the seed gets ready to grow. When this happens, it begins to consume its stored sugars, starting with the simplest monosaccharides (single-molecule sugars) first. These are the easiest sugars to perceive as sweet, and this continues until the drying process begins. In naturals, the continued presence of mucilage prevents the seed from germinating until it is dried, at which point the metabolism shuts down entirely. Additionally, some volatile compounds produced by flora as they ferment the cherry do seem to be absorbed into the seed and survive roasting as well. These compounds add fruity and floral aromas as well as a higher perceived sweetness in the cup.

 Naturally processed coffees are often kept in the dried cherry (as washed are kept in the parchment) until they are ready to be packed and shipped.