The ABCs of Coffee Beans

coffee beans

It is estimated that there are about 2.25 billion cups of coffee drank every day in the world. People from all over the world brew different types of coffee and have created numerous coffee drinks from it. If you are looking to create coffee drinks you have never done before or if you are simply looking to improve your coffee making, it’s good to know some basics on the coffee bean. We could go on with a complete book on the subject, but in order to get you going quickly, we have compiled a quick read for you to get the basics of coffee beans.

History of Coffee

Folklore has it that coffee beans were originally discovered in Ethiopia when a goat herder noticed his goats being full of energy after eating the fruit from a coffee plant. The goat herder took the fruit back to his village and gave some of the beans to some monks. They found themselves being awake all night and very energetic.

Since its discovery, it is believed that coffee fruit was used in many different forms including energy bars. In the 1500’s, the coffee drink became more popular and the coffee plant began getting exported from Yemen to places around the world. During the next 100 years or so, coffee plants were being grown in India, Europe, Java, the Caribbean, South America, and other parts of the world. Today, coffee beans are exported from all of these countries.

coffee beans

The Coffee Bean

The fruit from a coffee plant is small, round and will be red when ripe giving it a resemblance to a cherry. At the center of the fruit is a seed. This seed is what is known as the coffee bean and is the source for our coffee drinks. The seeds are processed in one of two different methods: wet or dry. The “wet” method soaks the beans for about 2 days and ferments them before final processing and drying. The “dry” method is simply a matter spreading the fruit out on brick or concrete and then letting them dry in the sun for 2 to 3 weeks. As the beans are processed, they are being verified for size, color, and other factors that affect the quality of the beans. Higher quality beans will cost more and will only be bought by higher end coffee manufactures while low-end beans may be bought by high volume companies.

Once the coffee beans have been processed to be sold for roasting, they are referred to as “green” coffee beans. Some will be green while others will have brown/yellow/reddish color combinations. If you are interested in roasting your own beans, these are the types of beans you will want to have.

Choosing the Beans

The two most important types of coffee plants are Arabica and Robusta. In general, these types of plants produce most all of the coffee sold in the world. From these plants there will be varieties such as Bourbon, Caturra, Jamaican Blue Mountain, and others. The Arabica plants produce about 70% of the world’s coffee. These beans are mild, lower in caffeine, and give an excellent aroma. Robusta beans are mostly grown in Central and Western Africa, Indonesia, Vietnam, and Brazil. Robusta is easier to grow than Arabica and therefore is less expensive. It is mostly used in blends and for instant coffees.

When selecting what type of coffee beans to use, you are not required to use only one type. In fact, numerous coffee producers will mix varieties to produce their own special blend. When buying coffee, note the source of the beans to give you an idea of what your preferences might be.

coffee beans

Roasting Coffee

Roasting coffee beans is the part that gives coffee its unique flavor and aroma. The vast majority of coffee is roasted in large commercial facilities, but there has been an increasing amount of “local” roasters all offering their unique flavors. As well, home roasting has been growing as coffee drinkers have been enjoying creating their own versions and giving themselves truly fresh roasted coffee.

The roasting process starts with sorting the beans and removing any discolored beans. Then the actual roasting occurs. This can be done with different methods. But, the two most common are drum or hot-air. A drum machine will rotate the beans while it is being heated from various sources. The rotation prevents burning and will roast the beans consistently. Hot-air roasters force hot air through a screen blowing the beans into the air. Thus, the beans are rotating in the air and evenly roasting the beans from the hot air. The amount of heat used, the time roasted, and other factors will affect the roast of the beans which affects the flavor. As the beans get hotter, they will change color initially going yellow and then to light brown and darker shades of brown. Because the beans absorb the heat, they will also continue to roast even after being removed from the heat and darken further.

Before there were companies selling coffee in grocery stores, many people needed to roast their own coffee beans at home. But, even with numerous large coffee producers today, people have been starting to roast their own beans for fun and being able to enjoy truly fresh and flavorful coffee. Home roasting can be done by simply roasting the beans in a cast iron skillet or by using a modern day counter-top roaster.

  coffee beans

Different Roasts

To get the desired roast of the coffee beans, the roaster will watch the temperature and color of the beans. The temperature can be watched on a thermometer or can be done by sound indicators. When a coffee bean reaches a temperature of approximately 196 °F, the beans will lose moisture and begin the make a cracking noise. This is known as the “first crack” and is the point where a coffee has reach a light roast. At this point, the roaster can let the roasting continue for a medium roast or a dark roast. Oils will being to appear on the outside of the bean. When the coffee gets to approximately 435 °F, the beans will begin to crack again. This is known as the "second crack". At this point, the beans are beginning to collapse. This is essentially the furthest you can roast the beans.

The different roasts from lightest to darkest are as follows along with the approximate temperatures the beans reach.

  • Cinnamon Roast (385 °F / 196 °C) – The lightest roast. Will have high acidity and a grainy flavor. This roast is accomplished by stopping just prior to the first cracking.
  • Light Roast (401 °F / 205 °C) – Will have a moderate light brown color and will display the unique flavors of the origins of the beans. The first cracking of the beans begins at this point.
  • American Roast (410 °F / 210 °C) – This is a medium light brown with slightly less acidity.
  • City Roast (426 °F / 219 °C) - Medium brown. Good balance of acidity and getting the flavor of the origin of the beans.
  • Full City Roast (437 °F / 225 °C) - Medium dark brown with some oil showing on the beans. Beans will begin the second crack at this point.
  • Vienna Roast (446 °F / 230 °C) - Moderate dark brown with a slightly oilier surface. Taste is slightly bittersweet and the less acidity. In the middle of second crack. The origins of the beans become less noticeable.
  • French / Espresso Roast (464 °F / 240 °C) - Dark brown with a shiny with oil surface. Will have a more burnt taste to it with low acidity. This is at the end of the second crack.
  • Italian Roast (473 °F / 245 °C) – The darkest roast. Beans are almost all black and shiny. The coffee will have less body and will have little acidity.

After Roasting

After roasting, the beans need to be cooled to prevent further cooking. This can be done with water or air. After cooling, the beans need to be packaged. The optimal shelf life on roasted beans is about 2 weeks. But, this is extended by removing exposure to heat, oxygen, and light. Therefore, proper packaging is necessary. Since the beans will emit CO2 several days after roasting, packaging will be done in pressurized canisters or foil-lined bags with pressure-relief valves.   

Once coffee is ground, it begins to lose its flavor after 15 minutes. Therefore, it is ideal to use the beans as soon as possible. If needed you can refrigerate or freeze the coffee to slow the staling process.