The coffee bean is actually the seed of the coffee plant. It is a small, potent, and highly popular seed used to brew the beverage consumed worldwide.

1. The Basics

· Plant Name: Coffee Plant (Coffea)
· Family: Rubiaceae
· Main Species: There are over 100 species of coffee, but the two most commercially important ones are:
  · Arabica (Coffea arabica): Known for its smoother, sweeter, more complex flavour. It accounts for 60-70% of the world’s coffee production.
  · Robusta (Coffea canephora): Has a stronger, harsher, and more bitter taste, with about twice the caffeine content of Arabica.

2. Where does a Coffee Bean come from?

· The Fruit: A coffee bean is the seed inside the bright red or purple fruit of the coffee plant, known as a “coffee cherry.”
· Inside the Cherry: Typically, a cherry contains two beans, flattened against each other. Occasionally, a cherry contains only one seed, which is called a peaberry. Peaberries are often considered to have a distinct flavour.

3. From Cherry to Bean: Processing

Getting the bean out of the fruit involves a crucial step called processing. The two primary methods are:

· Dry/Natural Method: The entire coffee cherry is dried in the sun. Once dry, the outer skin and pulp are removed to reveal the bean. This method often imparts a fruity, heavy body to the coffee.
· Wet/Washed Method: The pulp is removed from the bean first, and the beans are then fermented, washed, and dried. This results in a coffee with a cleaner, brighter, and more acidic flavour profile.

4. Physical Characteristics of a Green Coffee Bean

· Shape: Oval
· Size: Approximately 1 cm long.
· Colour: After processing, but before roasting, the bean is green (hence the term “green coffee bean”).
· Distinct Feature: A noticeable crease down the center.

5. Roasting: Where the Flavor is Born

Green coffee beans do not taste like the coffee we drink. The characteristic flavour is created through roasting, where the beans are heated to high temperatures. This process causes:

· Colour Change: Green → Yellow → Light Brown → Dark Brown → Almost Black.
· Flavour Development: The roast level dramatically changes the taste:
  · Light Roast: Light-bodied, acidic, and retains most of the bean’s original origin characteristics.
  · Medium Roast: More balanced, with a richer flavour, more body, and less acidity. This is the most popular roast level.
  · Dark Roast: Strong, bold, and smoky flavours dominate. The inherent flavours of the bean are often masked by the roastiness.

6. Key Chemical Components

· Caffeine: A natural stimulant that reduces fatigue and improves focus.
· Chlorogenic Acid: A significant antioxidant linked to various health benefits. Its content decreases during roasting.
· Oils: Such as Caffeol, which are largely responsible for coffee’s distinctive aroma and taste.