The world produced more than 8.7 million metric tons of coffee beans last year. The U.S. alone has been known to import as much as 123 thousand metric tons in a single month. In North America and Europe, the average ingestion of coffee is around a third of that of tap water; this means for every two cups of tap water drank, a cup of coffee is also imbibed. It’s clear that humanity has a bit of a love affair with this little brown bean. But how much do you really know about your “cup o‘ joe?” What is a coffee bean really, and where does it come from? These are all questions that we’re here to answer today. Let’s learn a little more about the world’s favorite caffeinated vice.
All coffee beans are derived from several species of shrubs in the Genus Coffea. The bean itself is actually the seed found inside of the bright red berries (actually considered cherries) that grow on the shrubs. The two main species of shrubs that are cultivated are Coffea arabica and Coffea canephora or, as it’s more commonly known, Robusta. The arabica strain is less bitter than the Robusta (due to lower caffeine content), and is grown more commonly — it makes up 75-80 percent of the world’s coffee market. Both are native to Sub-Saharan Africa. The plants can only be grown specifically between the tropics of Cancer and Capricorn (a latitudinal band that stretches from the middle of Mexico to the top of Argentina). Because of its specific geographic needs, the only U.S. state that commercially produces coffee beans is Hawaii. Nonetheless, more than 70 countries produce both arabica and robusta beans every year.
The top five coffee producers in 2011 (listed in order of greatest production) were Brazil, Vietnam, Indonesia, Colombia and finally the native turf of Ethiopia. These five countries alone produced over five of the 7.8 million metric tons of beans cultivated in 2011. But growing is only part of the journey — let’s look at how the bright red cherry is processed into the seed we are more accustomed to.
Once the crop is ripe (as is judged by the color of the fruit) the berries are then harvested, and the flesh is removed, leaving the seeds. Seeds are not completely clean — they are still covered in mucilage (a thick, gluey substance that plants produce to help germinate the seeds). The seeds are fermented to remove this, and then washed and dried. From there they are sorted and labeled as green coffee, ready to be exported or roasted. These little green seeds are still a far cry from the brown, aromatic beans we are familiar with. This is where roasting comes in.
Roasting is arguably the single most important factor in determining the overall strength and flavor of a coffee. The actual roasting process begins when the green coffee seeds reach about 390F. At this heat the beans begin to physically and chemically change. Physically they expand as moisture leaves the bean and they become less dense. From a chemical standpoint, the roasting begins to break down starches within the bean, turning them into simple sugars that begin to turn brown from the heat — creating the color of the beans. This process also creates aromatic oils that determine the subtler notes of the coffee’s flavor. Roasts are generally classified by the color of the bean — darker roasts are regarded as bolder, since a majority of the fiber has been eliminated, leaving mostly sugar, and almost all of the aromatic oils have been eliminated by prolonged heat. Lighter roasts are less bold, but have a subtler, more complex flavor due to preserved aromatic oils and lower sugar content. The roasting process actually has no effect on the caffeine content — this depends solely on the bean itself. After roasting we are left with that ubiquitous little bean that populates store shelves across the world, ready to bought and brewed in any number of ways.
So that’s the life of a coffee bean. From a bright red berry thousands of miles away to a warm steaming mug in your hands. Who knows how long humanity’s obsession with coffee will continue, but it’s been rooting itself in our lives for at least the last 600 years, and it shows no signs of slowing down.