How Does Coffee Processing Affect the Flavor?
Let’s imagine that you walk into a local roaster and see that they are serving an Ethiopian Yirgacheffe which was roasted a few days ago. You order a pour over and are excited to find that you love it! It’s fruity and chocolatey, smooth and full. Just exactly what you love in a cup of coffee.
A week passes and you are another coffee shop. You see that they are serving Ethiopian Yirgacheffe here, so you immediately ask for a pour over. Your expectancy looms as you watch the barista create the liquid that you are sure will bring you joy and satisfaction. You take it to your table and sniff. Well, it’s not exactly the same as last week’s but you’re still excited.
So you take a sip. Hmm…? Then another sip. Hmm again. Not only is it not exactly what you expected, it tastes almost nothing like last week’s version of your Yirgacheffe. How is this possible?
The reality is that the way that even though coffee beans may have the very same origin, the way that they are processed (meaning the way that the bean is removed from the fruit) has a distinct and notable impact on the taste.
What is Processing?
The processing of the coffee is simply a name for the way that the fruit is removed from the bean. Remember that our beloved coffee bean is actually a seed that sits inside of the fruit (cherry) of the coffee. In order to get the beans to a place where they can be roasted and ground and brewed, they have to come out of the fruit. There are a basically two ways (albeit there are variations) that this can be accomplished: wet and dry. Let’s take a look at both:
During the wet processing method, water is the central factor. This means that the outermost layer of the fruit (the skin) is washed away. Then the coffee cherries are placed in a vat of water to allow for quality control. As most of the cherries will sink, those that float on the top are discarded as defective. The washed coffee cherries are then fermented for a short amount of time (just a day or so) and the remaining fruit is finally washed off of the beans. The beans are dried out in the sun using either raised beds made of screens, large flat patios, or a mechanical means of drying.
The wet processing method is often preferred (particularly by large batch roasters) because it allows for a great deal of quality control and consistency in the flavor of the bean as well as the roasting outcome. Also, because of the natural float test, the quality of the beans may be more dependable and there is less room for error. This method is also faster than the dry method, which many farmers prefer.
Wet processing, of course, requires a great deal of water in order for this method to work, so it is obviously used in places that have easy access to significant amounts of water, such as Central America. Countries which value coffee based upon a perceived acidity are more likely to use the wet processing method. However, it does require a great deal of water and may be considered a less “natural” way to remove the fruit from the coffee beans.
Dry (or “Natural”) Processing
This is the original method that was used for processing when the beautiful discovery of coffee beans was made. The primary factor in this method is the time that it takes for the coffee beans to dry. The coffee fruit is picked and then directly dried on raised screen beds or large patios. Throughout the process the cherries are turned and raked in order to allow for even drying and, once dried, the layers of fruit are removed all at once.
Naturally (“dry”) processed coffees tend to have a flavor with more body (a heavier feel in the mouth) as well as lower acidity when compared to wet processed coffees. The flavor profiles of these coffees are typically more intense and exotic. These beans are often well-loved by small batch coffee roasters who are looking for more unique and artful flavors.
On the negative side, coffee beans which are processed in this way are more open to error due to the fact that they are hand-picked. There is more of a chance of defects, tainting, or lack of uniformity in the bean quality.
Other Types of Processing
Although the two processes discussed above are the most common, a few other variations exist on the processing of coffee beans, including a Wet/Dry method that actually combines the benefits of dry processing with the speed of wet.
Wet Hulled/Wet Milled is a process that does not pause for fermentation but instead uses a husking process (by hand) for removal of the fruit. Honey Prep is another process which takes the bean directly from de-pulping to drying patios without allowing the cherry to ferment. These types of processing are still being perfected in a few distinct countries but are not as common and would more likely be found only in unique, specialty coffee shops in a limited edition.
Most people don’t take a moment to consider the way that their coffee beans emerged from the fruit when they are enjoying a cup of Joe. However, this process of removal of fruit from the bean is critical to the quality and flavor of every cup. In addition to the type of plant, area grown, and roasting, the way that coffee is processed makes a huge impact on the ultimate product.
So the next time you’re ordering a cup of coffee or buying a bag of freshly roasted beans, find out how the coffee you’re about to drink was processed. This little bit of information can have a great impact on the way that your coffee tastes.