Where it Comes From

Coffee Bean Processing: Everything You Need to Know

To most average coffee drinkers, the means by which our coffee, or more specifically the coffee beans themselves, are processed may never cross our minds. Those who do ponder it may think that it’s a simple set of steps, likely assuming it’s as easy as planting a tree and picking the beans at their maturity. Little do they know that the fragrant aroma that stimulates our senses in the morning and gives us energy to get through our workday is the result of a much longer, much more complicated process.

Here’s a little insight into that process.

Planting and Harvesting

Much like how beans are the seeds of legumes (yes, beans are actually seeds) the coffee beans that we grind up are actually seeds as well. If your coffee beans were left undried and unprocessed, you could actually plant them and grow a coffee tree.

Coffee trees (who take roughly three to four years to reach bean-bearing maturity) will actually bear a fruit. This fruit is called a Coffee Cherry, and much like a regular cherry will be a bright red when it’s ripe and will contain that aforementioned seed.

While coffee bean harvesting has been largely taken over by machines that speed up the process, there are still places where hand pickers harvest only the ripe fruits, in a process called selective picking. In mechanized farms the fruits are strip picked in large quantities, independent of ripeness.

Processing the Coffee Beans: Pulping and Drying

After the coffee berries have been harvested, they need to undergo a process where the flesh of the coffee berries are removed. This is called pulping the cherries. The coffee berries are placed in special machines separating the flesh from the seed. This coffee seed, which will eventually become the bean we’re familiar with, will now undergo a fermentation process for a period of time. This process is done in order to remove the slimy mucilage coating, essentially residue from the pulping, from the coffee beans.

After the coffee beans have undergone the mandatory fermentation, they are thoroughly flushed with clean water. This process is to remove the foul smelling residue due to the fermentation process and the waste water is a main cause of pollutant.

The coffee beans are then dried under the sun or by machines, until the moisture level is roughly 10% before they can be packed for storage.

Another method, often referred to as the dry method, involves drying the whole berry in the sun. It normally takes about 10 to 14 days to complete the process with constant raking of the coffee beans to prevent mildew from forming. The process also involves covering the beans during the nighttime and during rain to prevent the beans from getting wet. This method is popular and widely used by coffee producers where water is scarce. At the end of the process the dried flesh is then physically removed, leaving only the coffee beans.

The dried coffee beans are then sorted and graded before they can be stored or shipped to buyers. At this stage, the coffee beans are referred to as green coffee beans.

Sometimes the coffee beans will undergo an additional aging process. The reason for this is because when coffee was first introduced in Europe, the beans used underwent a shipment process that took six months. This created a preference for more aged beans that stuck for many generations. To this day some coffee beans are additionally aged.

Roasting the Beans

Roasting is the final process that most coffee beans have to undergo before they are commercially marketed and sold.

When coffee beans are subjected to heat, the sugar and acid will begin to react releasing its delicious and iconic aroma. This happens when the temperature of the bean reaches roughly 400 degrees Fahrenheit. The coffee beans will also turn darker due to the caramelized sucrose being roasted. Roasting machines rotate and move the coffee beans which prevent the beans from burning. Once the beans are fully roasted, they are quickly cooled to prevent damage.

When roasting the green coffee beans, a lot of carbon dioxide is released as a by-product. The carbon dioxide released helps to “seal” in the aroma and flavor of the coffee beans. Depending on how the coffee beans are stored, it may take some time for them to reach their optimal peak flavor and aroma. After reaching its peak, it will start losing its flavor again.

A quick aside: It’s worth noting that it is also possible to purchase un-roasted coffee beans. Some people prefer to roast the beans themselves. If you are trying to roast your own coffee beans at home, be aware that you may not be successful during the first few times. You might over-burn your coffee beans during your first few tries or under-roast them. Never be discouraged, but try until you get the taste and flavor that appeals to you. Remember to process in small amounts to maintain the freshness of your coffee.

Grinding Beans and Brewing Coffee: The Final Steps

Before the roasted coffee beans can be brewed, you need to grind the coffee beans first. The coarseness of your coffee (essentially how finely or un-finely your beans are grinded) depends on your preference and the type of coffee-brewing method and machine used. It can range from coarse to very fine (example: the Turkish grind.) There are many types of brewing machines: if you’re using a percolator for example, a course coffee powder is suitable but if you are using an Espresso machines, an extra fine coffee powder is required.

It’s important to note that coffee grounds go stale mere hours after being grinded, so make sure to brew it right after grinding.

Conclusion

Coffee beans have to undergo a string of processes before it can be consumed. The final flavor of the coffee depends on many factors: the type of bean, the harvesting/drying/aging process used, the roasting process, as well as the grinding and brewing process. Different methods and different techniques will give rise to a variety of coffee flavors. That variety gives us a plethora of options to pick from as we’re getting our morning dose of energy.

Happy brewing!

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