Introduction:Want to dive deeper into the origins of a great cup of coffee? This article starts with the botanical characteristics of coffee, covering variety classification, suitable growing conditions, as well as harvest seasons and green bean processing techniques in major global producing regions, helping you build a comprehensive coffee knowledge system. Whether you're a beginner coffee enthusiast or a barista looking to refine your skills, this practical information will help you better understand every cup of coffee in your hand.
Coffee (scientific name: Coffea arabica) belongs to the Rubiaceae family in botanical classification and is an evergreen small tree or shrub, also commonly referred to as a coffee tree or Arabian coffee. Interestingly, Yemen was long considered part of Arabia, so the coffee trees exported from there came to be known as "Arabian coffee." As for the word "coffee," it originates from the Arabic word "Qahwah," originally referring to a plant-based beverage. Later, as trade expanded, people also called it by its place of origin, "Kaffa," until the 18th century when it was established as the "coffee" we know today.
The appearance of a coffee tree is distinctive, with lateral branches often extending horizontally and leaves usually growing opposite each other, occasionally in whorls of three. Flowers bloom in clusters of 2 to 10 at the leaf axils, emitting a delicate jasmine-like fragrance. The fruit is a drupe, oval in shape, with an internal structure from the outside in consisting of the outer skin, pulp, parchment, silver skin, and the innermost seed — what we know as the coffee bean. It's important to note that apart from the seed, the other parts generally have little practical value.
Coffee varieties can be broadly divided into small-bean, medium-bean, and large-bean types. Small-bean varieties typically have lower caffeine content but excel in aroma expression; medium-bean and large-bean varieties, on the other hand, have higher caffeine levels and relatively milder aromas. A common blend ratio in commercial coffee is 70% medium-bean and 30% small-bean, striking a balance between flavor and stimulation. In addition, each variety may include several to over ten mutant strains, and these subtle differences often create unique taste profiles.
Wild coffee trees can grow up to 5 to 10 meters tall, but for ease of manual harvesting, cultivated trees are usually kept under 2 meters in height. Coffee trees have the characteristic of simultaneously growing leaves, flowers, and fruit, with leaves that are typically elliptical in shape. The first flowering usually occurs when the tree is about three years old, with pure white five-petal tubular flowers that emit a faint floral scent, densely arranged at the leaf axils. The flowers only last for two to three days before withering, and then after about six to eight months, the fruit gradually matures.
Mature coffee fruit is commonly known as "cherry coffee" because of its strong resemblance to cherries — oval-shaped, about 1.5 centimeters in diameter, with colors changing from green in the early stage to yellow, and finally to a bright red. Each cherry typically contains two seeds (flat beans), though some contain just one (peaberry), and these seeds are the "green beans." Each coffee bean is encased in multiple layers of structure including the silver skin and parchment, with a sticky, pulpy pulp on the outer layer and an outer shell on the very outside. It’s worth noting that high-quality coffee beans often have a thicker parchment layer, which helps preserve freshness and maintain flavor stability.
Coffee trees are extremely particular about their growing environment. The ideal cultivation area is within the "coffee belt" between 25 degrees north and south latitude. Successful cultivation requires meeting five key conditions: a warm climate (18 to 25 degrees), annual rainfall of 1500 to 2250 millimeters synchronized with the flowering cycle; ample sunlight but with appropriate shading to avoid sun damage and ensure good ventilation and drainage; soil rich in nitrogen, potassium carbonate, and phosphates; altitude ranging from 500 to 2000 meters; and no frost throughout the year. Among these, the higher the altitude or the closer to the tropics, the more pronounced the regional flavor characteristics of the coffee tend to be.
From sowing to harvest, cultivating coffee trees requires patience and care. About 40 days after sowing, germination begins, with seedlings first raised in a greenhouse until they reach 40 to 50 centimeters in height, then transplanted to the farm. The seedling selection process at this stage directly affects the quality of future products and is also the primary checkpoint strictly controlled by many specialty coffee brands. Coffee trees typically enter the fruiting stage after 3 to 5 years, and then every 8 to 9 years the main trunk needs to be cut down to encourage regrowth. After 2 to 3 such cycles, the individual plant’s harvest period can extend for about 30 years. Some regions (such as Colombia and Ethiopia) plant shade trees to reduce direct intense sunlight, while areas with moderate sunlight conditions (such as Costa Rica and Brazil) do not require this.
Harvesting is a crucial step affecting coffee quality. Mature coffee cherries must be picked promptly, but since a single tree often has fruits at varying stages of ripeness, the harvesting process is often time-consuming and labor-intensive (usually lasting 4 to 5 months). If unripe fruits are mixed in, the final coffee's flavor performance will be noticeably reduced. To ensure freshness, harvested cherries need to be sent to receiving stations for processing on the same day, with low-quality fruits being screened out during transportation.
The harvest periods in major global producing regions vary: Brazil is concentrated between May and late June; Colombia and Central America are from October to late February of the following year; the Mocha region and Africa’s Arabica and Robusta varieties are also from early October to late January of the following year; Indonesia’s EK-1 variety is from March to late May. Taking Brazil as an example, many farms have dedicated receiving stations that conduct initial washing and flotation (pre-cleaning and floating) through water tanks — ripe beans sink to the bottom due to higher density, while unripe or rotten fruits float on the surface for easy removal.
The most common types of coffee beans on the market are mainly divided into two categories: Arabica (Coffea Arabica) and Robusta (Coffea Robusta / Coffea Canephora), along with the less common Liberica (Coffea Liberica) and Arabusta (Coffea Arabusta). Understanding these basic classifications is an important first step in exploring the world of coffee.
The above content is compiled by CoffeeHunters, a coffee news website.
