How Does Coffee Grow?

Coffee goes through many stages before it arrives on your doorstep or at a local cafe, ready to be brewed. Previously, we’ve looked at how coffee is processed and roasted. In this post, we’re going to examine how coffee grows, starting with the coffee cherry and working our way towards the tree.

Coffee Beans Are Pits of Coffee Cherries.

Coffee beans are the pits of coffee cherries, which slightly resemble grapes. Coffee cherries mature over several months, after a flower has bloomed for about a month. During their maturation, the cherries progress from a bright green to pink, red, dark red, purple and, eventually, black. This process for Arabica varietals takes about five to six months.

Farmers who provide the best lots selectively pick their cherries when the each cherry is dark red. Black ones are rotten, and even purple ones are past their prime. Many farmers can’t afford the labor costs of multiple pickings, so they strip pick their crops. In strip picking, all the coffee cherries are picked at once. Some farmers, like Luiz Rodrigues of Fazenda California, use machinery to selectively pick their coffee without incurring high labor costs. This produces a more uniformly ripe lot, but it requires harvesting equipment.

In the majority of coffee-producing countries, mature trees produce a single crop of cherries each year. In some countries that don’t have as well-defined a dry season, however, there are two harvests, a primary and a secondary one. Colombia is one such country.

Arabica Coffee Is Self-Pollinating.

As mentioned, coffee cherries mature after a flower has bloomed and fallen off. On Arabica coffee trees, flowers are self-pollinating. (Robusta plant’s aren’t self-pollinating.) Self-pollination has benefits for both growers and roasters. Farmers don’t need to worry about pollinating their crops. Roasters appreciate the uniformity that self-pollination provides. Because there’s only one set of DNA used to produce the coffee beans, there’s not much variation among a single tree’s beans.

Coffee Grows on Trees, or Shrubs.

Coffee cherries and blossoms grow on small evergreen trees, or shrubs. An untamed coffee tree can grow up to 16 feet tall. Most farmers, however, prune them back annually to between 5 and 7 feet, which is a comfortable height for picking. Pruning annually also increases the trees’ yields.

Coffee farmers must be careful to protect their trees from sunlight, because coffee trees haven’t evolved to withstand direct sunlight for extended periods of time. Even an unpruned, 16-foot coffee tree would sit well below the forest’s canopy, so taller plants would filter out any direct sunlight. When not protected by a canopy, just three hours of afternoon sun could dry out and kill a plant. In addition to cultivating shade-grown coffee, farmers can help their plants survive the hot sun by:

• planting their trees on east-facing slopes, where the sun only shines in the morning
• ensuring their trees are well-watered
• selecting hardy varietals

Along with shade, Arabica coffee likes the following conditions:

• temperatures between 59 and 77ºF
• an annual rainfall of 59 to 118 inches (preferably on the lower end of this range)
• elevations above 1,800 feet, up to 6,300 feet

Because Arabica plants thrive at higher elevations (Robustas do well closer to sea level), farmers who grow Arabica varietals sometimes can’t use machinery to selectively pick their crops. Even if they are able to afford the equipment, slopes high in the mountains are sometimes too steep to use the harvesting machinery on. Growers with farms at high elevations, therefore often must pick their crops by hand — and pay additional labor costs if they selectively harvest cherries.

Coffee Trees Are Planted During the Rainy Season. Most coffee-growing countries have distinct dry and rainy seasons. Trees are planted during the wet season, because it’s easier to dig holes, and the roots are able to spread through the moist soil. Traditionally, farmers would dig a hole during the rainy season and place 20 unprocessed seeds in the hole. About half of these seeds would germinate, and the farmer would select the healthiest sapling of the bunch. More recently, seedlings are started indoors in greenhouses and then transplanted into fields. This method has a higher success rate.

Farmers won’t see crops from new trees for 3 to 4 years, and the total life span of a tree is between 25 and 30 years. When it’s at its peak, a coffee tree will produce 1 to 1½ pounds of roasted coffee a year.