Now that you know how to differentiate different types of beans depending on where in the world they came from, it’s time to face the next step. In fact, there’s quite a long process involved between picking fruit from the coffee plant to drinking your Starbucks latte and a lot of additional factors that can affect your drink’s taste. For example: how coffee is washed. Here’s a quick roundup of what “washed” coffee even means and how to notice the difference in your cup.
But first things first: To understand how coffee is processed, you have to understand the structure of the fruit itself. Generally, the fruit can be identified as having two main parts: the pericarp and the seed. The seed is probably something most people in the world immediately recognize as a coffee bean. But the pericarp — and how much is washed off — also greatly affects the taste. The pericarp consists of four parts: the skin, the flesh of the fruit, the mucilage (a thin slippery layer composed of natural sugars and alcohols) and the parchment (the hull that encases the bean). Picking completely ripe coffee fruit is extremely important to the taste and quality of the bean. You can usually tell a bean is perfectly ripe when it has a uniform “red wine” or “burgundy” color throughout, though keep in mind that certain types coffee can also ripen into a yellow or orange colors. Without further ado, the washing process:
In the washed process, processors completely remove the mucilage and skin outside the parchment with friction, fermentation and water. After harvesting, the coffee fruit is sliced open, and the beans are taken out of the cherry, leaving only the mucilage as the outermost layer. Then the coffee can be either fermented to naturally break down the mucilage (this can take six hours or four days) or the mucilage can be removed with mechanical demucilagers, which remove a specific amount of mucilage with friction. Though this is a relatively new technology and pretty expensive, using a mechanical demucilager may actually be a more efficient coffee-processing method, as it requires much less water and creates less waste, all the while giving the farmer greater control over his bean. Either way, washed coffee means that 100 percent of the mucilage is removed, so the bean dries and rests with the parchment as its outermost layer. Washed coffee tends to be clean, bright, fruity, more acidic, lighter-bodied and mild.
Semi-washed coffee requires pretty much the same method as washed coffee; the coffee is simply left with a certain percentage of mucilage on its parchment. Leaving this stick-sweet layer actually makes the drying of the coffee much more difficult, and the beans must be rotated extremely often to prevent fermentation and rotting. Semi-washed coffee tends to have an intense sweetness, more body and less acidity than washed coffee, in addition to being a more uniform cup.
This is the original coffee-processing method. For the natural process, the entire coffee fruit is dried with all the layers intact. This encourages natural fermentation, and beans are only removed once the fruit is the texture of a fruit leather. Natural coffee tends to have lower acidity, intense exotic flavor, and more body. But the process is so hands-on and so based on visual detection that there tend to be more defects and less consistency.
Contact Agnes Zhu at [email protected].