What is Coffee?

Ever wondered, when you pour your steaming morning cup of joe: what exactly is coffee?

It’s black, tasty (I hope) and energizing.

But WHAT is it?

The grounds don’t grow on trees.

You probably know they come from coffee beans. But what are those? And where do they come from. I myself had only a vague idea of a bush in the tropics that has berries that somehow become coffee beans. But, I wanted to know exactly what’s what. So, I took a deep dive in the world of coffee and now I’m ready to share my findings with you.

The Short Answer

First, I’ll give you the short answer:

Oxford English Dictionary provides two definitions for the word “coffee”:

  1. a hot drink made from the roasted and ground bean-like seeds of a tropical shrub.
  2. the shrub which yields coffee seeds, native to the Old World tropics.

So, both the beverage and the plant are coffee. The plant grows cherries. The cherries have seeds. And when these seeds are roasted and then ground, you can pour water over them to generate your cup of coffee. Easy. That’s your short answer.

The slightly longer answer to the question – “what is coffee?” – is actually a lot longer.

There is a vast number of things to tell about coffee. You could write a book about it (and quite a few have).

I am not going to do that. I’ll give you the condensed version. I will tell you all the basics and the really interesting stuff. But it won’t take you all day to read this article ( in fact, depending on your reading speed it will take you 10 to 15 minutes). 

So, get yourself a cup of dark goodness and sit back.

The Coffee Plant

The coffee plant, or Coffea, is the type of plant which produces cherries of which the seeds are the basic raw material for our beloved beverage. Some say that instead of coffee plant we should say coffee tree. This might be more accurate because in the wild this plant/tree can grow up to 33 feet (10 meters) in height. Cultivated plants however, are typically pruned at 10 to 12 feet (3 to 3.5 meters) for easier harvesting of the cherries. But, for simplicity’s sake, we’ll stick with coffee plant. There are between 25 and 100 species of coffee plants. The specific genus of Coffea was first described in 1753 by the Swedish botanist Carolus Linneaus. He described the Coffea Arabica, one of the most familiar variants, in his Species Plantarum. Because the characteristics of different coffee plants can vary widely, botanist have disagreed on the exact classification ever since Linneaus recorded his classification. The species you should be interested in are the Coffea Arabica and the Coffea Canephora. These produces the most common beans you might know as Arabica and Robusta. More on those later.

The leaves of the coffee plant can be as small as 1 inch (2.5 centimeters) or as large as 16 inches (40 centimeters) and vary in color from purple to yellow to dark green. A few years (generally, 3 to 4 years) after the coffee plant is planted, white sweetly smelling flowers grow in clusters around the leaves. After the flowers have been pollinated it takes between 30 and 35 weeks for the coffee cherries to mature and be ready for harvesting. At that time, the cherries change color from green to red.

The ideal conditions for growing coffee plants can be found at specific parts of the world. Located between latitudes 25 degrees north and 30 degrees south, around the equator, is the optimal zone for growing coffee. This zone is commonly known as the Bean Belt (sometimes also called the Coffee Belt). The 60 inches (150ml) of rainfall that is necessary for the coffee plant to flourish combined with the rich soil and mild temperatures needed is found in this zone.

Bean Belt

Image courtesy of Ohio State University

The picture above shows that the Bean Belt centers around Africa, the Caribbean, Central and South America, India and South East Asia. In total, more than 50 countries commercially produce coffee. Largest coffee producers are Brazil, Vietnam, Colombia and Indonesia.

Types of Coffee Plants

As mentioned earlier, it is estimated that there are between 25 and 100 species of coffee plants. But, in the commercial coffee industry two species dominate the market. The Coffea Arabica or Arabica Coffee accounts for 75-80 percent of the world’s coffee production and the Coffea Canephora, commonly known as Robusta Coffee, accounts for the remaining 20-25 percent. The Robusta producing plants are more durable and resistant to diseases and changing weather conditions, but their taste is considered inferior to the taste of Arabica coffee. Also, Robusta beans have a higher caffeine content.

Beans from the Coffea Arabica are generally of higher quality and have taste properties that are generally more acidic, less bitter, and contain a lower caffeine content. It is thought to be the first type of coffee plant to be cultivated and is also known as the coffee shrub of Arabia and mountain coffee. Specialty coffee variations are mostly varieties of the Arabica coffee bean. You might hear or read terms like Bourbon coffee, Columbia, Ethiopian Heirloom. These are all different kinds of coffee varieties from the Arabica family.

The Coffee Bean

The seeds of the cherry that grows on the coffee plant are the coffee beans we know. The cherry is, as an ordinary cherry, a so-called stone fruit. And while the coffee beans are in fact seeds, they are called beans because of their resemblance to true beans (you know, kidney beans, lima beans, etcetera). As you can see in the cross section of a cherry in the picture, each cherry contains two beans.

Harvesting the Coffee Bean

When the cherries of the coffee plant are (preferably) ripe and turn from a green to a red color, they are harvested. There are two harvesting methods:

1. Strip Picking

As the name suggests, all cherries are removed from the plant, regardless of their state. This means that both green (unripe) and red (ripe) fruits are removed. Strip picking can be done either manually or using mechanical strippers. If the cherries are manually ‘stripped’ the pickers usually place a canvas on the ground and then pull the branch outward, and knock all coffee cherries of the branch and collect them from the canvas.

Mechanical harvesting can take two forms. The first is like manual strip picking, but with the use of a Derriçadeira. A sort of Edward Scissorhands on a stick. This contraption has moving fingers which beat the cherries from the branches onto the canvas on the ground, where they are collected.

The second form of mechanical strip picking makes use of harvesting machines that beat around the bush (pun intended). This machine beats the coffee plant with mallets that knock of the cherries into collection units.

A Derriçadeira

A harvesting machine

There is a mayor downside to strip picking. Both ripe and unripe fruits are removed from the plant using this method. Unripe cherries contain seeds (the beans) that are not fully matured and eventually produce a much more bitter flavor and sharp odor. You might guess that coffee cherries harvested through strip picking are used to produce cheaper beans for mass consumption.

2. Selective Picking

Selective picking is a far more labor-intensive and fully manual picking process. Only the ripe (red) fruits are picked. Experienced picker can pick up to seven baskets a day. Pickers visit plants every eight to ten days during the harvesting period to check which cherries are ripe for picking. This method is used to harvest the finer Arabica beans for higher end and specialty coffee.

Processing Coffee Beans

After picking we have a bunch of cherries, but still no beans. And certainly, no steaming cup of coffee. Yet. The fruit covering the beans needs to be removed. This can be done either through a wet process, dry or a semi-dry process.

In the wet process the cherries are sorted by immersing them in water. The bad or unripe fruit that got through stays afloat while the good ripe fruit will sink. The skin and some of the pulp of the cherry is removed by pressing the cherries through a screen with holes smaller than the cherries but larger than the beans. The bean still has a significant amount of pulp or mucilage attached to it, which need to be removed.

This removal process is either done by fermentation and washing or by mechanical scrubbing.

In the ferment and wash-process the pulp is removed by fermenting the beans with microbes and then washing them thoroughly. By first soaking the beans and pulp in water or the fruits own juices with microbes for up to 36 hours, the cellulose in the pulp breaks down and is easily washed of.

This process needs to be carefully monitored to ensure that the beans don’t go sour. After fermenting the beans are washed either by hand or in special washing machines. As you can imagine, a lot of water is used in this process.

After the removal of pulp the beans need to be dried. A ‘fresh’ bean will contain approximately 60% moisture. The drying process brings the moisture content down to 11 or 12 percent. To dry the coffee, the beans are usually spread out on patio’s and left to dry in the sun. The beds of coffee beans are regularly raked to help the drying process. How long it takes for the coffee beans to dry depends on the processing method (i.e. either wet or dry) and can take anywhere from 6 up to 14 days. In most cases sun-drying cannot bring the moisture content in the beans down to the desired 11 or 12 percent. That’s why the beans are generally transferred to a mechanical dryer when the moisture content reaches 15 percent.​

Processing coffee beans through the dry process is the original method of producing coffee and has been used for centuries. Harvested cherries are sorted and cleaned. Unripe, overripe or damaged fruits are discarded and any dirt, leaves or twigs are removed. The whole cherries are then placed on patios or drying tables and left to dry in the sun. For even drying the cherries are regularly turned and raked. This also prevents mildew. The whole drying process can take up to 4 weeks, depending on weather conditions. Sometimes, on larger plantations, the process is sped up by mechanically drying the cherries after they have been in the sun for a few days. The dried cherries are then transported to a special mill where the cherries are hulled to remove the dried pulp.

There is one last processing method: semi-dry. This is a process mainly used in Indonesia and Brazil and is essentially a hybrid between wet and dry processing. The outer skin of the cherries is removed mechanically and the pulp-coated coffee beans are then stored for about a day. After a day, the pulp is washed of and dried in the sun.

Conclusion

There are many things to say about coffee. In this articles we’ve only scratched the surface of the world of coffee. We haven’t said anywhere near enough about brewing the perfect cup of coffee, the tools which make a coffee lovers’ life easier or better, or other things you can try if you are in to coffee. For now though, we’re done. I hope you enjoyed reading this article.

If you have any comments, please share them below.

Cheers,

Monsieur Coffee

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