Coffee Growing and Harvesting
From seedling to coffee cup!
The traditional method of planting coffee is to place 20 seeds in each hole at the beginning of the rainy season. This method loses about 50% of the seeds’ potential, as about half fail to sprout. A more effective method of growing coffee, used in Brazil, is to raise seedlings in nurseries that are then planted outside at six to twelve months. Coffee is often intercropped with food crops, such as corn, beans, or rice during the first few years of cultivation as farmers become familiar with its requirements. Coffee plants grow within a defined area between the tropics of Cancer and Capricorn, termed the bean belt or coffee belt.
Of the two main species grown, arabica coffee (from C. arabica) is generally more highly regarded than robusta coffee (from C. canephora); robusta tends to be bitter and have less flavor but better body than arabica. For these reasons, about three-quarters of coffee cultivated worldwide is C. arabica.
Coffee plants are grown in rows several feet apart. Some farmers plant fruit trees around them or plant the coffee on the sides of hills, because they need specific conditions to flourish. Ideally, Arabica coffee beans are grown at temperatures between 15–24 °C (59–75 °F) and Robusta at 24–30 °C (75–86 °F) and receive between 15–30 cm (5.9–11.8 in) of rainfall per year. Heavy rain is needed in the beginning of the season when the fruit is developing, and less later in the season as it ripens.
A coffee bean is a seed of the coffee plant, and is the source for coffee. It is the pit inside the red or purple fruit often referred to as a cherry. Just like cherries, the coffee fruit is also a so called stone fruit. Even though the coffee beans are seeds, they are referred to as ‘beans’ because of their resemblance to true beans. The fruits – coffee cherries or coffee berries – most commonly contain two stones with their flat sides together. A small percentage of cherries contain a single seed, instead of the usual two. This is called a “peaberry.” The peaberry is more unusual occurring only between 10 and 15 percent of the time, and it’s a fairly common (yet scientifically unproven) belief that they have more flavour than ‘normal’ coffee beans.
Harvesting and Processing Coffee Cherries
Coffee berries and their seeds undergo several processes before they become the familiar roasted coffee. Berries have been traditionally selectively picked by hand; a labor-intensive method, it involves the selection of only the berries at the peak of ripeness. More commonly, crops are strip picked, where all berries are harvested simultaneously regardless of ripeness by person or machine. After picking, green coffee is processed by one of two methods—the dry process method, simpler and less labor-intensive as the berries can be strip picked, and the wet process method, which incorporates fermentation into the process and yields a mild coffee.
Then they are sorted by ripeness and color and most often the flesh of the berry is removed, usually by machine. Some use automated depulping machines and some use hand crank depulping machines.
After pulping the coffee cherry, the two parchment beans, surrounded by a fruity slimy mucilage are transferred by conveyor belt and water to the fermentation tanks. Here the beans are immersed in water with an added enzyme, which accelerates the fermentation break down of the fruity mucilage in a controlled environment and most importantly within managed time frames, so as not to affect the bean.
The treated mucilage can then be easily washed off, leaving a clean finished wet-parchment bean for future drying procedures.
When the fermentation is finished, the seeds are washed with large quantities of fresh water to remove the fermentation residue, which generates massive amounts of coffee wastewater. Finally, the seeds are dried.
The best (but least used) method of drying coffee is using drying tables. In this method, the pulped and fermented coffee is spread thinly on raised beds, which allows the air to pass on all sides of the coffee, and then the coffee is mixed by hand. In this method the drying that takes place is more uniform, and fermentation is less likely. Most African coffee is dried in this manner and certain coffee farms around the world are starting to use this traditional method.
Next, the coffee is sorted, and labeled as green coffee. Another way to let the coffee seeds dry is to let them sit on a concrete patio and rake over them in the sunlight. Some companies use cylinders to pump in heated air to dry the coffee seeds.
Wet Processing
Dry Process
The next step in the process is the roasting of the green coffee. Coffee is usually sold in a roasted state, and with rare exceptions all coffee is roasted before it is consumed. It can be sold roasted by the supplier, or it can be home roasted. The roasting process influences the taste of the beverage by changing the coffee bean both physically and chemically. The bean decreases in weight as moisture is lost and increases in volume, causing it to become less dense. The density of the bean also influences the strength of the coffee and requirements for packaging.
The actual roasting begins when the temperature inside the bean reaches approximately 200 °C (392 °F), though different varieties of seeds differ in moisture and density and therefore roast at different rates. During roasting, caramelization occurs as intense heat breaks down starches, changing them to simple sugars that begin to brown, which alters the color of the bean.
Sucrose is rapidly lost during the roasting process, and may disappear entirely in darker roasts. During roasting, aromatic oils and acids weaken, changing the flavor; at 205 °C (401 °F), other oils start to develop. One of these oils, caffeol, is created at about 200 °C (392 °F), which is largely responsible for coffee’s aroma and flavor.
The degree to which coffee beans are roasted is one of the most important factors that determine the taste of the coffee in the cup. Before roasting, green coffee beans are soft, with a fresh “grassy” smell and little or no taste. The coffee roasting process transforms these raw beans into the distinctively aromatic, flavorful, crunchy beans that we recognize as coffee.
The perfect roast is a personal choice that is sometimes influenced by national preference or geographic location. Within the four color categories, you are likely to find common roasts as listed below. It’s a good idea to ask before you buy. There can be a world of difference between roasts.
Light roasts
Light brown in color, this roast is generally preferred for milder coffee varieties. There will be no oil on the surface of these beans because they are not roasted long enough for the oils to break through to the surface.
Light City
Half City
Cinnamon
Medium roasts
This roast is medium brown in color with a stronger flavor and a non-oily surface. It’s often referred to as the American roast because it is generally preferred in the United States.
City
American
Breakfast
Medium dark roasts
Rich, dark color, this roast has some oil on the surface and with a slight bittersweet aftertaste.
Full City
Dark roasts
This roast produces shiny black beans with an oily surface and a pronounced bitterness. The darker the roast, the less acidity will be found in the coffee beverage. Dark roast coffees run from slightly dark to charred, and the names are often used interchangeably — be sure to check your beans before you buy them!
High
Continental
New Orleans
European
Espresso
Viennese
Italian
French
Coffee Grind Types
The objective to gourmet coffee brewing is to get the most flavors out of the coffee bean when infused with hot water. This starts with properly matching the style of coffee maker with the correct coffee grind. There are many types of grinding methods.
Types Of Coffee Grinds
Coarse- Distinct large bulky grounds of coffee, much like heavy grained kosher salt.
Medium – Gritty just like that wonderful beach sand.
Fine – Smooth to the touch and a little finer than granulated sugar and table salt.
Extra Fine – Finer than granulated sugar but not yet powdered.
Turkish – The finest grind yet which looks like flour and feels like powder.
Great coffee starts with great beans. The quality and flavor of your coffee is not only determined by your favorite brewing process, but also by the type of coffee you select. There can be a world of difference between roasts, so check out our roasting types guide.
Some of the flavour factors include:
What country is the coffee from, and what region?
What is the variety? Or is it a blend?
Do you favour a dark roast coffee, a light blend or something in between?
What kind of grind have you selected?
While there are a lot of choices, remember that there’s no right or wrong — you can choose a dark, flavourful espresso roast coffee and still have it ground to be brewed in a drip system. Have fun trying and enjoying different combinations.
Purchase coffee as soon as possible after it’s roasted. Fresh-roasted coffee is essential to a quality cup, so buy your coffee in small amounts (ideally every one to two weeks). Store it in airtight dark containers in a cool place to keep it as fresh and flavourful as possible.
Brew and enjoy!
