Now that you have a fresh batch of ripe coffee cherries, it is time to start the harvest. After a hard day’s work, you can now look forward to enjoying a delicious cup of coffee.
The world’s top coffees are processed using many different methods, which can be grouped into four categories: Wet Processing (Washed), Dry Processing (Natural, Sun Dried), Pulped Natural Processing, and Semi-Washed Processing.
Wondering what the difference is between natural processed coffees and washed processed coffees? Here’s a rundown of the different coffee processing methods, with more detailed explanations linked out.
Wet processed coffee
The wet processing method is considered to be the least natural and most heavy-handed approach to processing coffee as it strives to remove the fruit and all residual pulpy plant matter from the coffee cherry, leaving only the coffee bean.
The first step in the wet processing method is to soak the coffee cherries in water. This allows fermentation to take place, which separates the cherry from the bean. The coffee cherries can also be run through a mechanical depulper to remove them. Once the green coffees are removed, they are washed again to remove any residue. Finally, the coffee beans are placed outside to dry on a patio or raised beds.
Washed coffee is more highly sought after among coffee enthusiasts because it gives a purer coffee experience, reflecting the coffee farmer’s hard work. A lot of attention and thought goes into cultivating coffee, from choosing an optimal environment to build the farm to the soil’s nutrient content. By removing the fruit, washed processing gives customers access to the intrinsic flavor of the coffee.
The taste of the coffee is more “pure” than other methods – not influenced by the coffee cherry.
Dry processed coffee (natural process)
Dry processing has the advantage of being easier than washed processing. With dry processing, the coffee cherries are harvested and processed without any intermediate steps, so there is less setup and effort required.
The dried fruit can be turned into coffee flour if there are the right facilities. If not, it is thrown away as waste.
Farmers who grow coffee beans risk their entire income if their harvest is ruined by rain or high humidity, which can lead to the development of mold and fungus. The beans gain unique flavors through a process that takes at least two weeks without sun to allow for drying.
Dry processed coffees usually don’t have a lot of different flavors, because the flavor is always pulled towards fruity and sweet because of the coffee cherry. Dry processing is especially common for coffees from Brazil, Ethiopia and Yemen.
The amount of water used is another key consideration – dry processed coffees may use as little as a gallon per kilogram of dried parchment, while wet processing requires closer to 10 gallons for the same quantity.
A key drawback of dry processing coffee is that, by leaving the cherry attached to the seed, the coffee bean can absorb sugar and flavors from the fruit. This can make the underlying flavor that farmers worked hard to emphasize gets lost behind a wall of sweetness.
Coffee parchment is the product of coffee beans that have been dry processed. The fruit remnants on the coffee beans cause the brewed coffee to have more body. Wet processed coffee has a more desirable level of acidity.
Dry processing is less reliable than washed processing because coffee cherries vary in size and consistency, so they dry at different rates. Every batch of coffee is different because it is not possible to control how the coffee cherries dry.
A dry-processed coffee will have more body than a wet-processed coffee due to the fruit remnants left in with the coffee beans.
Wet processed coffee is often considered by coffee connoisseurs to be better than dry processed or natural coffee, but it is really just a matter of personal opinion.
Dry processing is a method of coffee processing where the coffee beans are dried without the use of water. This method is also known as “pulped natural”, “semi washed”, “dry milled” or “honey coffee”.
Honey processed coffee
Is there a middle ground between dry and wet processing? Honey processing is a best-of-both-worlds happy medium.
Honey processing involves removing some of the cherry from the coffee bean, but not all of it like in washed processing. The amount of cherry left on the bean affects the degree of honey processing, with less cherry meaning the coffee is closer to dry processing, and more cherry meaning the coffee is closer to washed processing.
The coffee is then laid out on patios or raised beds to dry. In the pulped natural or “semi dry” process, coffee cherries are only partially removed. This leads to coffee beans with varying levels of sweetness and color, depending on how much of the coffee cherry was removed. The coffee is then dried on patios or raised beds.
Many people believe that honey processing coffee beans is the best way to produce coffee. This method is sweeter than the washed processed coffee, but not as sweet as the natural-processed coffee. This type of coffee has complex fruity notes.
Wet hulled/semi washed
The coffee beans are pulped at the farm to remove the coffee down to the parchment and mucilage. Then, the beans are sent to a processing facility where they are ground down. This process is known as “Giling Basah” (wet grinding) in Indonesian countries.
Processing methodology is typically passed from generation to generation within a country. Government organizations and international coffee organizations sometimes step in to provide alternate methods or share their techniques, which helps raise the standards across the industry.
There are some methods that farmers can’t use because they don’t have access to the right equipment, or because the equipment is too expensive. This is especially a problem in places where water is scarce. It’s hard to believe, but in many parts of the world where coffee is grown, the farmers don’t have the same level of knowledge or access to technology that we do in first world countries.
Pulping coffee
Pulping is a process in which the outer flesh of the coffee cherry is removed. This is typically done within 24 hours of harvesting the cherry, using a machine known as a pulper. The pulper rough rollers to loosen and break up the outer part of the coffee cherry.
Demucilaging, drying and hulling
After the coffee cherry’s mucilage is removed, the cherry is placed in a fermentation tank for 12 to 24 hours.
The coffee beans are dried using either forced-air drying or sun-drying.
Hulling or husking is a process where a machine called a huller is used to remove the parchment and silverskin from the beans, as well as polishing them. At this stage, the beans are known as green coffee beans.
Aquapulp coffee processing
Aquapulp is the process of removing the freshly-picked coffee cherry’s sticky pulp, or mucilage, through mechanical demucilaging. This process uses machines to scrub the cherry and remove the pulp.
Although the traditional wet processing methods of removing the mucilage through fermentation and washing are still in use, the aquapulp process is gradually becoming more popular.
After the parchment is removed, the coffee beans are sorted and graded based on local standards, which vary in different regions. Generally, the beans are sorted into quality grades based upon size, shape, and other factors.
Grading coffee
The following text is about screens with graduated hole sizing and vibrating air tables. These tables help to graded the beans by density and to isolate defective coffee beans. This helps improve the final product’s taste.
Coffee silverskin
Some coffee processors who sell whole green coffee beans leave the silverskin on the bean since it serves as a protective barrier and then crumbles off naturally as chaff during the coffee roasting process. Other coffee processors prefer to polish off the silverskin.
Roasting coffee
The last step in making coffee is roasting the beans. This involves heating them in a coffee roaster to change their physical and chemical properties. This gives the coffee the desired flavor and smell.
Coffee roasting is a process that eliminates most of the moisture in coffee beans and starts a series of chemical reactions called pyrolisis. These chemical reactions change the coffee beans’ composition and create coffee compounds that are associated with the flavors and aromas of brewed coffee.
The goal of a skilled roastmaster is to find the perfect balance of time and temperature to bring out the best flavors in the coffee beans being roasted.
Roastmasters carefully watch the color of the coffee beans as they roast and expand. The beans can range in color from very light to very dark, and as they lose moisture, they also change in density.
The coffee roasting process affects the fragrance, body, taste, sweetness/bitterness, acidity, and aroma of the coffee beans, which in turn affects the brewed coffee.
Roasting
Coffee roasting machine
To roast coffee beans, you need to be skilled and have the right coffee roaster. Most roasting machines are heated by propane gas, with electricity powering a drum. The temperature for roasting coffee beans ranges from 370 to 540 degrees Fahrenheit (188 to 282 degrees Celsius).
The time it takes to roast coffee beans varies from 12-30 minutes. The beans will shrink in size by 20% as they darken in color and become fragrant. 25 pounds of green coffee beans usually take around 15 minutes to roast. You will get about 1 pound of roasted coffee from 8 pounds of coffee cherry.
Fluid bed roasters
The coffee beans are placed in a roasting chamber and heated from below by a stream of hot air. The heat and the constant agitation of the beans causes them to expand and release their oils. A Fluid Bed Roaster is a type of coffee roaster that agitates coffee beans using a column of hot air, similar to how a popcorn popper works. The coffee beans are placed in a roasting chamber and heated from below by a stream of hot air. The heat and agitation of the beans causes them to expand and release their oils.
Roasting time
The amount of time it takes to roast coffee beans varies depending on several factors, including the quality and moisture content of the beans, as well as the weather conditions where the roasting is taking place. The age of the beans can also affect roasting time.
The main determining factor in how long to roast coffee is the desired roast level, with options ranging from light to dark.
The skilled roastmaster carefully monitors the roasting time and temperature, as well as more subtle aspects such as the appearance and fragrance of the coffee beans, to ensure a perfect roast.
The roastmaster waits for the sound of the coffee beans popping or cracking. These sounds happen at particular times during roasting.
Grinding
The coffee beans are roasted and then ground up to be made into a drink.
Coffee processing: Final thoughts
We hope this guide has given you a better understanding of how coffee is processed and how that affects the final taste. It’s important to choose a processing method that aligns with your expectations if you want to get the best possible flavor from your coffee.