From the Plant to a Brewing Cup of Coffee
A ripe coffee cherry plucked today may take several months to reach your cup. It goes through a series of steps in processing, and the result is the fine, rich and aromatic coffee.
From the plantation to the brewing, the coffee has a long and arduous journey.
1. Planting the coffee seeds
Large beds are used to plant coffee seeds. The seeds are generally grown in shaded nurseries. When sprouts appear, the seedlings are removed and planted in individual pots. The soil used in these pots is carefully formulated and balanced. These plants are watered regularly and protected from bright sunlight, until they are strong enough to sustain themselves. Thereafter, they are permanently planted. Usually the permanent planting is done during the rainy season so that the soil remains moist while the roots of the young plants become strongly anchored in the soil.
2. Collecting the harvest
The newly planted coffee trees start bearing fruits in about 3 or 4 years. The ready-to-be-harvested cherries can be identified by their bright, deep red color. The ripe cherries are either strip picked or selectively picked by hand. In most countries there is only one coffee crop a year, but in some there can be two crops a year. Approximately 100-200 pounds of cherries can be collected by a good picker in a day which amounts to about 20-40 pounds of coffee beans.
Strip pick method- This method is suitable for flat plantations on large scale fields. It can be either done by hand or machines. All the cherries of the branch are stripped at one go, and the entire crop is harvested at one time.
Selective pick method- This method is labor intensive and costly, as the pickers rotate through the plantations and pick by hand, the cherries which are the most ripe. The method is used to collect finer arabica beans.
3. Processing through dry and wet method
Processing of the beans starts as soon as possible after the beans are picked. There are two methods of processing the beans, and any one of the methods can be used depending upon the locations and availability of local resources.
The dry method- The dry method is used in countries where there is scarcity of water. The picked cherries are spread on huge surfaces are dried under the sun. They are raked and turned several times to prevent spoilage. The cherries spread for drying are covered during night time and during rains to prevent them from getting wet. The process may take several weeks before the moisture content becomes as low as 11%. The dried cherries are then stored in warehouses, and later sent for milling.
The wet method- During this method, the skin and pulp of the coffee cherries are removed by passing them through a pulping machine. The washed away pulp is dried and used as mulch. The beans are conveyed through water channels where the light beans separate from the heavy ripe beans that sink to the bottom. These ripe beans are passed through rotating drums that separate them according to their size. The separated beans are then fermented in water-filled tanks for 12 to 48 hours. This process separates the thick mucilage layer attached to the parchment. These beans are rinsed in water and then dried till moisture content drops to 11%.
4. The milling process
- The milling of coffee beans is done through following processes:
- Hulling is done to remove the dry husk of the dried bean cherries.
- Polishing is done through polishing machines which remove any extra silver skin that remains after hulling.
Sorting is done to separate coffee beans by size and weight. Beans are also assessed for flaws in color and structure and the imperfect ones are removed. The sorting can be done through machines or by hand while the beans move along an electronic conveyor belt. The bean size is measured on a scale of 10 to 20. The number represents the size of a round hole's diameter in terms of 1/64's of an inch. A number 10 bean would be the approximate size of a hole in a diameter of 10/64 of an inch and a number 15 bean, 15/64 of an inch.
5. Export of coffee beans
The coffee beans, after going through milling process, are referred to as 'green coffee'. These are packed in jute or sisal bags and exported. The worldwide production of green coffee is approximately seven million tons.
6. The coffee taster
Tasting a coffee is an important process and is done to ensure the quality and taste of the coffee. The process is called cupping and is done in special rooms. The coffee taster is called the cupper and is capable of tasting hundreds of samples of coffee a day. The first step is to evaluate the beans for its overall visual quality. The beans are then roasted, grounded and brewed in temperature-controlled boiling water. The cupper ‘noses’ the brew to assess the aroma that indicates the quality. The coffee is left to rest for several minutes before ‘breaking the crust’ by pushing aside the grounds at the top of the cup. Thereafter, the coffee is nosed again and then slurped with quick inhalation. In this manner, coffee is evaluated for quality, and determining different blends and roasts.
7. Roasting and grinding
Coffee is roasted roasting machines that maintain a temperature of about 550 degrees Fahrenheit. The beans are kept moving to avoid burning. When their internal temperature reaches 400 degrees, the otherwise green beans start turning brown. The process of roasting also helps to remove the oil called caffeol, from the beans. The roasted beans are immediately cooled either by air or water.
Grinding is the next step after roasting and is responsible for the flavor. The extent of grinding depends upon the method of brewing is to be followed. The finer ground coffees should be brewed more quickly than the course ground.
8. Brewing the coffee
The ground coffee can now be brewed as per your preference about the aroma and taste.