Coffee Bean Guides

What Are Coffee Beans? – A Complete Introduction to Coffee Beans

Coffee beans are the seeds of a coffee cherry, the fruit of a coffee tree or shrub. So technically, coffee beans are not “beans.” The name likely originated due to their resemblance to actual beans. However, for coffee lovers, it is more than just the seeds of a plant. Rather, coffee beans are the holy grail of any coffee enthusiast.

Where do Coffee Beans Come From?

Historically, the first ever coffee plant originated in the Ethiopian Plateaus. It was discovered by the goat herder, Kaldi, around the 9th to 14th century. Since then coffee cultivation has spread around the world.

So the question now really is “where is coffee grown?”

Coffee beans are produced in over 50 countries worldwide, but most of them are grown in the “Bean Belt”, also known as the coffee growing regions. 

The bean belt is a horizonal strip across the equatorial regions of the globe. It encompasses Central and South America, Eastern Africa, and Southeast Asia.

As you will see later, the geographic origin of your coffee beans is important because it is one of the factors that influences the taste of your final brew. This is also why big coffee establishments, such as Starbucks or Peet’s, have a section on their menu just for single-origin coffees.

What are the Different Coffee Bean Types?

Although there are 124 distinct coffee bean varieties, there are only 4 main types of coffee beans commercially cultivated. The most common ones are Arabica beans and Robusta coffee beans. Arabica beans make up about 70% of the total coffee production in the world, while Robusta constitutes the other 30%. On the other hand, Liberica and Excelsa bean are part of coffee blends.

arabica beans

Arabica Beans

Aroma: Delicate. Floral, Fruity.
Taste: Sweet, Smooth, and Tangy.
Caffeine: 1 to 1.5%
Acidity: Medium
Fun Fact: Arabica is the most common and popular coffee bean.

Robusta Beans

Aroma: Robust. Earthy, Woody, Nutty.
Taste: Bold, Bitter, Full-Bodied.
Caffeine: 2 to 3%
Acidity: Low
Fun Fact: Robusta is cheaper to cultivate and commonly used for instant coffee.

Liberica Beans

Aroma: Exotic. Woody, Fruity, Floral.
Taste: Spicy, Woody, Smoky.
Caffeine: ~1.3%
Acidity: Low to Medium
Fun Fact: Liberica has an unusually large coffee cherry compared to other varieties.

Excelsa Beans

Aroma: Distinct. Spicy, Tropical, Earthy.
Taste: Tart, Fruity, Wine-like
Caffeine: ~1%
Acidity: Medium to High
Fun Fact: Excelsa is often used in coffee blends to enhance its overall flavor profile.

Check out the difference between Arabica and Robusta beans.

How are Coffee Beans Processed?

Once coffee cherries are harvested, it’s time to procoess them.

Coffee processing transforms coffee into the green coffee beans that we roast and brew. Essentially, it involves removing several outer layers of the coffee bean, including the outer skin, pulp, mucilage, parchment, and the silver skin.

Coffee Cherry Layers (© Klingel, et al.)

Processing impacts the taste and flavor of the final coffee product becuase sugars in the pulp of the coffee cherry undergo metabolic reactions in this stage.

There are many ways to process coffee beans. But generally, it can be classified into three:

Wet or Washed Process

Most commercially available coffee beans are wet-processed. This method of processing involved de-pulping and fermenting beans to remove the outer layers of the coffee cherry before drying.

Wet processed coffee beans are reknowned for producing bright and acidic coffees.

Dry or Natural Process Coffee

Natural processed coffee beans are made by allowing the entire coffee cherry to naturally dry. This method imparts a fruity and sweet flavor on the coffee beans because the pulp and mucilage, which contains sugars, were not stripped off.

Pulped Natural or Honey Process

Honey process is a coffee processing method that combines the practices of both washed and natural processes. In this method, the outer skin of the coffee cherry is removed, but most of the mucilage is left to dry.

This method results in coffee beans that exhibit a balanced of sweetness, acidity, and complexity when brewed.

More specialized or newer ways to process coffee involve the following processes:

  • Double washed coffee processing
  • Co-fermentation coffee processing
  • Anaerobic coffee processing
  • Wet-hulled coffee processing
  • Thermal shock coffee processing
  • Strawberry coffee processing

After processing, we are left with raw, green coffee beans that’s spongy and tastes grassy, vegetable-like, and bitter. Roasting is necessary to transform them into the brown and roasted beans we commonly see.

Why are Coffee Beans Roasted?

Literally, roasting coffee beans is the act of cooking raw coffee beans to extract the flavors and aromas inherent to the beans. This creates the various rich and complex amalgamation of flavors that we all enjoy.

There is a whole complex science of roasting coffee beans. But in simple terms, roasting leads to thousands of rapid chemical reactions that break down cell structures and pulls out moisture from the beans as they are subdued to high temperatures. This process also makes coffee beans crunchy and soluble, for easy grinding and brewing.

Factors such as the temperature and length of roasting affect the final brew. Often, roasters have their own preferences. But generally, coffee roasts fall into one of the color categories:

Light Roasts

Synonymous with:

Light City Roasts
Half City Roasts
Cinnamon Roasts

Medium Roasts

Synonymous with:

City Roasts
American Roasts
Breakfast Roasts

Dark Roasts

Synonymous with:

Espresso Roasts
French Roasts
Italian Roasts

However, in recent years, medium-dark roasted coffee beans have also grown in popularity because they offer a sweet spot between the boldness of dark roasts and the brightness and complexity of the lighter roasts.

Coffee Bean Taste Profile

Coffee has undeniable flavor complexity. The coffee bean types, geographic origin, as well as its processing , roasting, and brewing methods, all have an impact on one’s overall sensory experience. But what makes coffee good or bad?

Well, it really depends on your personal preference. But most of the time, if you’re not a trained coffee expert, you might find it difficult to describe the specific taste or smell of the type of coffee you enjoy. Educating yourself with the flavor notes and common coffee aromas can help you refine your taste, get to know your preferences, and have a more delightful coffee experience.

A useful tool to understand more about coffee flavors is a flavor wheel. Thanks to the combined efforts of the Specialty Coffee Association of America (SCAA) and the World Coffee Research (WCR), the Coffee Taster’s Flavor Wheel below has more than 110 coffee attributes such as flavor, aroma, and texture that can help us better understand our coffee preferences.

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