When purchasing coffee beans, we often see information on the packaging such as the variety, grind size, roast level, and sometimes even flavor descriptions. It is rare to find any mention of the size of the beans, but in fact, this is also an important criterion for measuring quality.
Sizing Classification System
Why is size so important? How does it affect flavor? Does a larger bean always mean better quality? Before delving into these questions, let’s first understand some basic concepts.
During the processing of coffee beans, producers sort the beans by size through a process called “screening.”
Screening uses multi-layered sieves with varying mesh sizes ranging from 20/64 inches (8.0 mm) to 8/64 inches (3.2 mm) to differentiate the beans’ sizes.
These sizes, from 20/64 to 8/64, are referred to as “grades” and are typically used to assess the quality of coffee beans.
Why is Size Important?
Generally speaking, the larger the coffee bean, the better the flavor. This is mainly because the beans have a longer growth and maturation period on the coffee tree, which allows for the development of richer aromas and flavors.
Among the two main coffee species, Arabica and Robusta, which account for 97% of global coffee production, the largest beans are called “Maragogipe,” ranging from 19/64 to 20/64 inches. However, there are exceptions, such as the small and concentrated “Peaberry” beans, which will be discussed later.
Different Size Grades and Their Characteristics
Beans measuring between 18/64 and 17/64 inches are industrially classified as “Large” beans. Depending on the origin, they may have specific names like “Supremo” (Colombia), “Superior” (Central America), or “AA” (Africa and India). If you see these terms on the packaging, it usually indicates high-quality coffee beans. These beans mature for a longer period, and after proper processing, their flavors are quite pronounced.
Next are the “Medium” beans, measuring between 15/64 and 16/64 inches, also known as “Excelso,” “Segundas,” or “AB.” Although they mature for a slightly shorter period, with proper processing, they can achieve or even exceed the overall cupping quality of larger beans.
Beans measuring 14/64 inches are referred to as “Small” beans (also called “UCQ,” “Terceras,” or “C”). These are typically considered lower-quality beans, though their flavor is still acceptable. However, this rule is not absolute. For example, in Ethiopia, where smaller beans are predominantly produced, with proper processing, these small beans can also yield rich flavors and aromas.
Beans smaller than 14/64 inches are called “Shell” beans and are usually used in cheap coffee blends. However, there is an exception — “Peaberry” beans, though small, are highly regarded as premium beans.
Exceptions
Maragogipe Beans
Maragogipe beans are mainly produced in Africa and India, but due to their large size, they are prone to uneven roasting, which can lead to an imbalanced flavor profile. Therefore, they are not considered high-quality beans. However, this issue is specific to Arabica and Robusta varieties.
There are also two smaller species that account for 3% of global production — Liberica and Excelsa. These species produce larger beans, similar in size to Maragogipe beans, but because the beans are harder, they are more stable during roasting and are considered high-quality.
Peaberry Beans
Peaberry beans range from 8/64 to 13/64 inches in size. While small in volume, they are often regarded as the most flavorful and aromatic “specialty coffee,” sometimes referred to as the “essence of coffee.”
Factors Affecting Coffee Bean Size
The size of coffee beans is primarily determined by the variety, but environmental factors such as climate and altitude also play an important role.
If the soil, climate, and altitude are not ideal, the beans of the same variety may be half the average size, which often results in lower quality.
Moreover, even under the same conditions, the maturation rate of fruit on the same coffee tree can vary. As a result, a single harvest may include beans of different sizes.
Conclusion
After reading this article, many people might start paying attention to the size of coffee beans when selecting beans for their fully automatic coffee machine. This is a good thing because now you understand the significance of bean size on flavor.
That said, many coffee machine owners also mix different-sized beans, skillfully adjusting varieties, roasting, and brewing methods to create stunning flavors.
Post time: Feb-21-2025
