Introduction
Coffee is one of the most popular beverages in the world. With the rising demand for coffee comes an increasing variety of coffee types and styles available to consumers. While all coffee comes from the coffee plant or coffee tree, different growing and processing methods result in distinct classifications of coffee beans and brewed coffee drinks. This paper provides an overview of the main classifications of coffee through a research and analysis of peer-reviewed literature on coffee taxonomy and production methods.
Types of Coffee by Brewing Method
One way coffee can be classified is by its typical brewing method. The three main types based on how the coffee is prepared for drinking include espresso, drip coffee, and cold brew coffee.
Espresso is a strong, concentrated coffee brewed by forcing hot water under pressure through finely ground coffee beans. Espresso machines use a pump to force nearly boiling water through a tightly packed basket or portafilter containing finely ground coffee. The intense high pressure water extraction yields a thick syrupy liquid containing a high concentration of caffeine and other compounds. A typical espresso shot is around 1-2 fluid ounces.
Drip coffee, also known as filter coffee, is made by pouring hot water over coarse-ground coffee beans contained in a paper, cloth or metal filter. As the water slowly drips through the beans, the coffee compounds dissolve into the water to make the finished brewed coffee below the filter. Drip coffee has a lighter body than espresso and is the most common type prepared at home using drip coffee makers or pour-over methods.
Cold brew coffee involves soaking coarse-ground coffee in room temperature or cold water for an extended period, usually 12-24 hours. The long, slow steeping process at lower temperatures results in a less acidic brew with a smoother flavor profile than hot brewing methods. Cold brew concentrates are then diluted with water, milk or other liquids before drinking. This method is growing in popularity for its unique taste and ability to be enjoyed iced.
Types of Coffee by Bean Variety
Beyond brewing methods, coffee varieties can also be classified based on the specific coffee bean strain or cultivar. The two main species of coffee tree cultivated for production are Coffea arabica and Coffea canephora, more commonly called robusta. Arabica varieties account for about 60% of global coffee production and are noted for their complexity, clarity and balance. Robusta varieties tend to have higher yields but produce a stronger, more bitter cup of coffee.
Within Arabica there are further sub-classifications based on factors like country of origin, processing method and varietal characteristics. Some of the most common Arabica coffee varieties grown around the world include:
Ethiopian coffee: Renowned oldest coffee varieties from Ethiopia with floral, berry-like notes.
Kenyan coffee: Bright, acidic and lively cups from Kenyan high-altitude plantations.
Colombian coffee: Known for cocoa and caramel flavors from Colombia’s volcanic soil.
Latin American bourbon varieties: Soft, balanced coffees descended from 19th century Yemeni beans in Brazil, Mexico, etc.
Yemeni Mocha coffee: Spicy, chocolatey varietals prized for centuries from Yemen’s coastal highlands.
Hawaiian Kona coffee: Aromatic, smooth style from hand-picked beans on volcanic slopes of Big Island.
Within robusta, there are also subtypes but the varietals are generally classified together as robusta due to its more assertive taste characteristics compared to Arabica fine coffees. Some examples of robusta origins include Vietnamese, Indian and Congolese coffee.
Processing Methods Define Coffee Types
Beyond bean variety, how the coffee cherries are processed after harvesting also defines broad classifications of coffee. The wet and dry processing methods produce coffees with distinct chemical makeups and sensory profiles.
Wet processed (washed) coffee: Involves removing the outer fruit pulp from the beans through fermentation and washing before drying. This removes some acidity resulting in a smoother cup. Most specialty-grade coffees use the washed method.
Dry processed (natural or unwashed) coffee: Leaves the outer fruit layer on during sun-drying which decreases moisture more rapidly. This intensified drying process caramelizes some of the sugars for a sweeter, more complex flavor at the cost of increased acidity. Examples include Yemen Mochas and dry-process Guatemalans.
Pulped natural coffee: A hybrid method that removes the outer fruit before sun-drying the beans with their dried parchment layer intact.
Blends Define Coffee Classifications
While varietals and processing define single-origin types, blending also serves as an important classification in commercial coffee. Quality roasters and brands create unique coffee blends by carefully combining different varietals, origins, processing styles and/or roast profiles with the goal of producing balanced, consistent flavors across batches. Popular global blends include Breakfast Blend, House Blend, Dark Roast, Medium Roast, Decaf and Flavored varieties infused with syrups, spices or chocolate. Seasonal and limited release blends allow roasters to experiment and innovate with new coffee combinations.
Conclusion
Through exploring factors like brewing methods, bean varieties, processing techniques and blending approaches, this research has outlined the major classifications that define the spectrum of coffee types available. With the global coffee market constantly evolving, new coffee varieties, production methods and preparation styles will continue to emerge and expand options for coffee growers, roasters and consumers worldwide. Coffee classification provides a framework for understanding and comparing the complex flavors within this diverse and nuanced beverage.
Andrew Stroud