Coffee starts out as a small white flower a bushy tree. A month later the flower turn brown and falls off the tree leaving a tiny green bud behind. The green bud grows bigger and changes color from green to yellow to red over a period of 6+ months. We call this fruit a coffee cherry. Once the cherries ripen they are ready to be picked. . With a simple twist and pull they will come off easily.

Harvesting: all across the world farmers make use of 3 different harvesting methods : Strip Hand picking | Mechanical | Selective hand Picking

Strip Hand picking :

Once the field is dubbed ripe for the harvest, pickers will head out to pick off every cherry from the tree. From yellow to red. The cherries are then sorted by color at the washing bay.

Mechanical :

A harvester is used to ride over the rows of coffee trees and mill out all the cherries from the trees. The cherries are caught in a big basket at the back. The machine collects all the cherries from the trees, yellow or red. The cherries are then sorted by color at the washing bay.

Selective Hand picking :

Only the ripe cherries are picked by hand. This is a time consuming project that will require pickers to visit a tree up to 7 times during a single harvest period. The yellow cherries are left on the tree to develop and only then are they picked off.

After harvesting, the cherries must be processed to remove the outer skins of the coffee cherry. The methods of processing are unique from farm to farm and is determined by the elevation of the farm , how much water they have to their disposal and space for drying.

Depulping

The coffee cherry is picked, it is either depulped or released into a fermentation chamber where some bacteria, natural enzymes, and other microbes reduce it. Depulping — a mechanical process is involved in removing its outer layer. Using a big turning wheel machine with water that breaks open the cherry skin to separate flesh from the seeds. This discloses a sticky and sweet layer called the pulp mucilage.

The Methods of Processing

The 3 main ways of processing are washed, honey and natural methods.

The washing method of processing coffee is mostly used in areas where there is availability to plentiful water. Once the coffee cherries have been sorted by color they are poured into water. Here all the floating cherries are separated, they are deemed 2nd grade cherries, and then is depulped.

Washing

After that final sorting the 2 groups of cherries are de-pulped. Thereafter the seeds are floated in water again to separate the floating beans from the rest, those that sank to the bottom are left in the water to fermentate.

This helps the pulp release from the bean in order the be removed completely.

The beans are then washed using a hard broom to wash of the remaining pulp from the beans, mainly using water (or, less regularly, in its juices), revealing the parchment. At this particular point, the beans are dried in the sun or in a mechanical dryer to dry. They are rotated with brooms 8–10 times a day.

Once the coffee is dried to a proper level over a period of 20–30 days, it is then hulled to remove the parchment, exposing the greenish-blue seed and the silver layer.

The fully washed coffee will tend to be a bit bright, with delicate fruit notes, and consistent color and taste. It will have less body compared to the same coffee processed using a honey or natural method but stands a greater chance of being consistant bean to bean and therefore cup to cup.

Honey process

*Semi washed | *Natural pulped

*Semi Washed:

Semi washed yellow : After floating the 1st time, the cherries are de-pulped and then rinsed in water and transferred to drying beds to dry. Complete drying can last between 30–60 days. The beans are raked about 7 times a day to ensure even drying.

Semi washed white : Same as with Semi washed yellow : the beans are floated and de-pulped and rinsed in water, the difference here is the cherries are then washed using a hard broom and mainly water to wash off the remaining pulp from the beans. At this point, the beans are transferred to drying beds to dry for a duration of 30–60 days, rotated about 7 times a day to ensure even drying.

Natural processing

Natural pulped: As it names suggests, the natural process is a natural procedure of processing coffee, dating back to the initial commercially manufactured coffee beans for the Ottoman Empire of Yemen. Rather than picking coffee, washing and pulping, the cherries are just picked from the crop and directly transferred to the drying beds with skin, fruits and all. The cherries are dried as is for about 55–80 days in the sun.

Red honey : These beans will turn to a faint red color because of the natural pulped process, hence why it is called red honey. Fermentation happens on the drying beds itself, removing the pulp by brushing the beans 5 times a day to rotate them in the sun.

Black honey : same natural pupled and drying process — These beans will turn to a black color in the sun due to the beans not being disturbed so much. They are only rotated twice a day.

When the coffee cherry is dry, the skin is easily stripped off, and only the bean is left behind. The coffees processed using this method are inconsistent compared to coffees produced using the washed process and can experience quality issues if not correctly sorted. Even so, they have a subtle tartness that we can identify as berry or fruit while they rage acidity.

Natural coffee that has been improperly processed has an almost sour wine-like, fermented taste.

Reason for Roasting coffee

Being a seed and an agricultural product, coffee must be roasted to make it ready for consumption. The process uses time and heat to turn the raw and green seed into a brown coffee bean. Typically, the roasting process lasts between 9 to 15 minutes and passes through several chemical reactions to impart aromas and flavors on the final product. The lighter roasted coffees will own more ‘process’ notes like fruit, berry, and floral tea. The darker roasted coffee will be bittersweet chocolate and smoky. As the roasting process proceeds from light to dark, the features of the coffee will fluctuate. For instance, in the case of sweetness, a lightly roasted coffee will start with sugarcane, proceed to raw sugar, caramel, and then to maple syrup.

In the art of roasting coffee, roasters put their single sip on coffee. On the other hand, in the science of roasting, the roasters attempt to repeat their procedure, fight variables, and make a consistently good product for your consumption.

Roasting

Slow Temperature Increase: First, green coffee beans are placed in a roaster and heated. As the roaster heats up, the beans are tumbled like clothes in a dryer to allow the heat to toast the coffee evenly. The temperature is slowly raised to between 460°F and 530°F, allowing heat to penetrate slowly to the center of every coffee bean.

First Color Change: Green coffee beans contain a significant amount of moisture, and you’ll notice the release of a significant amount of steam. As moisture escapes the roasting coffee, the green coffee beans will first turn yellow, then turn different shades of brown.

First Crack: When the temperature reaches a critical point, the coffee beans will swell (increase in size) significantly. Soon thereafter, you will hear a loud cracking noise as the remaining moisture bursts out of the coffee beans. At this point, the sugars in the coffee have begun to caramelize and the coffee is officially considered “roasted”. At the time of first crack, however, the beans are at the lowest roast level (we’ll explain the roast levels a little later).

Rapid Second Color Change: After the first crack, the coffee beans caramelize and release oils quickly. During this phase, the coffee roasts very quickly. The color darkens rapidly and requires quite a lot of finesse and timing to achieve different precise roast levels. Usually the roasting process is stopped sometime during this phase.

Second Crack: another loud crack will be heard, and this is called the Second Crack. Most roastmasters stop the roast before the second crack, but sometimes the second crack is desirable. The second crack is usually harder to identify than the first crack, and the coffee is very dark roasted by the time the second crack occurs, if it occurs at all. If the coffee is roasted much beyond the second crack, all of the sugars in the coffee will have caramelized, yielding a very harsh, bitter cup of coffee.

Stopping the Roast: The roastmaster uses the aroma and color (and sometimes special instruments) of the coffee to determine when the coffee beans are done roasting. It takes a tremendous amount of experience to know exactly when to stop the roasting process. For precise timing and profile matching, many higher-end roasters make use of computer-controlled mechanisms. Regardless of whether you are using a digital profile or roasting manually, a key part of roasting is to STOP roasting at the right time. To make sure the beans stop roasting immediately, the beans must be cooled quickly. Cooling is usually performed by either flooding the roaster with fresh cold air, or by spraying the beans with water. Most professional roasters immediately dump the roasted coffee from the roasting chamber into a type of silo designed to pass air through the beans while rotating them. The faster the air is moving across the most surface area of the beans, the faster they cool… it’s like blowing on your food to help it cool faster.

Degassing After Roasting: After the coffee is roasted, the beans go through a process called degassing. For approximately 24 hours after roasting, the bean releases Carbon Dioxide (CO2) gas. The degassing phase is critical and should not be ground or brewed until all of the CO2 has been released.

Roasting coffee is both a science and an art

It takes a couple of years of learning and practicing to become an expert roaster with the capability to “read” the beans and make choices with instant timing. The main difference between a ruined batch and perfectly roasted coffee can be a concern of a few seconds.

Identify your roasts

Roasting coffee causes the sugars, fats, and starches contained in the bean to emulsify, caramelize, and release. The delicate coffee oil that results from roasting is what gives coffee its unique, distinctive aroma and taste.

In general, lighter roasts tend to be sharper and more acidic than darker roasts. Darker roasts have a fuller flavor, though. Coffee that is over-roasted tends to have a smoky, charcoal-like, or burned flavor (not desirable). Interestingly, darker roasts actually have less caffeine than the lighter roasts. Every coffee is different, though. Colombian coffee will taste different than Sumatra coffee, even if the roast level is exactly the same.

Light Roasts (Cinnamon, Half City, Light, New England) The bean is light brown and dry with no visible oils on the surface of the bean. The flavor is baked or bread-like, similar to toasted grain. Depending on the coffee, some sour tones may be present and the body of the coffee will be minimal. New England roast (not very common) is a little darker than Cinnamon roast.

Medium Roasts (American, Breakfast, Brown, City, Medium) Medium light brown beans. The American roast is the most common roast used for cupping and professional coffee tasting. An official Medium or City roast (more common in the Western U.S) is slightly darker than American (more common in the Eastern and Southern U.S.), and is an excellent choice for tasting the differences between most varietals.

Roast profiles: from green beans, to dark/burned roasted beans

Medium-Dark to Dark Roasts (Full City, Light French, Viennese) Medium dark brown beans. Some oily drops will be present on the surface of the bean when roasted Full City. Full City roasted coffee will exhibit some chocolate or caramel undertones. Light French or Viennese is ever so slightly darker than Full City.

Dark/High Roasts (After Dinner, Continental, European, French, New Orleans, Espresso) At this level, the beans are very dark brown (but not black). French roasted beans are shiny with an oil coating on the surface. Some burned undertones will be present and acidity is lower. This is a popular roast for making espresso, though lighter roasts are used also. Many people believe French roast to be the darkest roast, but they have not had Spanish roastyet…

Very Dark Roasts (Dark French, Italian, Spanish) Spanish is the darkest roast of all (Dark French and Italian is a little lighter). The coffee beans are nearly black in color and the flavor tends to be flat with charcoal undertones. Pretty much all of the sugar in the beans has been caramelized and toasted thoroughly. Most Americans would turn their noses up to coffee this overcooked but, hey, to each his own.

In conclusion

When receiving your coffee, it has been through a very long process to change it from a raw spongy seed into a substance that fuels our lifestyles, it also builds a social environment, and provides enjoyment to many people in their day to day life. Roasting creates new experiences with tasting coffee, evaluating it , and entirely enjoyment of masterfully roasted coffees that reach your home. Make the best of each bean that you can get your hands on and learn different ways to brew it – learn the science and art of coffee.