How Coffee processing and fermentation affect the Flavor of Coffee introduction to traditional Coffee processing

Many coffee drinkers go through the morning jolt without much thought. But coffee is far more complicated than throwing ground stuff into the machine and getting to work. In fact, coffee begins with a fruit called a cherry, whose seeds are removed, dried and fermented to become coffee beans. They are then baked, packaged and placed on the shelves where we buy them.

The fermentation process is crucial to shaping coffee's flavor because, like wine, it breaks down sugar through yeast and bacteria to produce acidity and fruity flavors in the cup. Because coffee cherries begin to ferment soon after picking, how farmers or local cooperatives handle this process directly affects the final flavor of coffee.

Processing methods vary by geography, climate, logistics and tradition, but the three main types are natural solarization, honey treatment and washing.

Natural sun coffee process

Similar to natural wine, natural coffee has minimal processing intervention, which means as little as possible to alter the fermentation that occurs naturally inside the cherry. In fact, the natural coffee process is the oldest technology and requires the least amount of water or electricity.

Natural coffee is fermented and dried, and each coffee bean undergoes internal fermentation for up to 30 days (weather permitting). No layer of cherries is removed before packaging for export.

Since fruit needs to be dried outdoors in dry, warm conditions, moisture or rain can cause serious problems, such as spoilage. To promote even drying and air flow, producers rake fruit on elevated beds, terraces or drying tables. Drying coffee is a more dangerous process than washing because it requires more attention and therefore more labor, and therefore carries a higher risk of spoilage or overfermentation.

Honey processing coffee technology

During honey processing, the skin or pulp of coffee cherries is removed within 24 hours of harvest. A portion of what remains-mucus, also known as honey-remains on the seed as it dries, and the amount left determines the style and flavor of the final coffee. Mucus is fermented on beans for 18 to 25 days and has a lower risk of spoilage than natural, while achieving similar flavor effects.

Costa Ricans take the concept of honey to new heights, using color terms-yellow, red and black-to denote the amount of mucus remaining, which indicates subtlety or intensity of taste. Yellow is milder, while black is closest to natural coffee.

Description: Usually creamy and sweet (taste, not sugar), with caramel, caramel, jam, blackberry and blueberry notes, and even toasted and stewed, like alcoholic Barossa Shiraz from a hot year.

Country: Brazilian coffee pioneered this technique known as natural pulp, but Costa Rican coffee has moved up the category and the technique is catching on in Central America. Fine coffee producers also like the nuances this method can create.

Coffee washing process

Washing coffee is the most common-and probably the most water intensive-processing method. Within 24 hours of harvest, the rind and most of the flesh of cherries are mechanically removed with a thresher. The beans are then fermented in open tanks (stainless steel, cement or even plastic vats) for about 18 to 36 hours, sometimes up to 72 hours, or even days for "wet" or underwater fermentation.

The fermentation method and amount of water used depends on resource availability and wastewater treatment options (it can be toxic), but essentially, the process breaks down the remaining slime so it can be removed or rinsed off with more water. This method is a traditional treatment and is used worldwide for its simplicity and efficiency.

Less time required means less labor and fewer opportunities for error, such as spoilage mentioned in the previous method. In addition, wet processing naturally picks out inferior cherries, which weigh less than "good" cherries and drift away with the waterways.

Description: Terroir driven cup with clean acidity and bright, clear flavor, depending on the country of origin.

Country: This method is used in almost all coffee-growing areas, except where water resources are scarce, such as Yemen. If the packaging of the product does not involve a process, it is likely to be washed.