Does Coffee Bean Size Matter? The Truth About Size, Quality, and Taste

When it comes to coffee, size might grab your attention, but does it really matter? Coffee beans come in all shapes and sizes, depending on their variety, origin, and processing. But does bean size indicate quality, or is it just a detail that makes no difference to the taste of your morning brew? Let’s grind through the facts (pun intended) and see what’s behind the bean.

Coffee Bean Size: A Genetic Thing

The size of a coffee bean is mostly in its DNA. Some beans are naturally large (like the famous Maragogype, aka "elephant beans"), while others, like the tiny Mocca beans from Yemen, are small but mighty.

Even within the two most common coffee types—Arabica and Robusta—there are differences. Arabica beans tend to be bigger, more elongated, and have an "S-shaped" curve on their flat side. Robusta beans are smaller, rounder, and often straighter.

So, size is heavily influenced by genetics, but does that mean bigger is better? Not necessarily. The quality depends more on how the coffee was grown, harvested, and processed.

The Climate Connection

Coffee is a natural product, and nature loves to mess with things. Coffee cherries grow under varying conditions, meaning no two beans are exactly the same. Factors like climate, soil, and altitude can affect bean size, even within the same plant.

For example, cherries that get more nutrients grow bigger, while others might remain smaller. To bring some order to the chaos, coffee beans are sorted by size before roasting. This process, called screening, ensures consistency, especially when roasting large batches.

Does Size Equal Quality?

If you’re comparing beans of the same variety, larger beans might be better because they often received more nutrients. But size alone isn’t a reliable indicator of quality. The Specialty Coffee Association (SCA) grades coffee based on multiple factors—size is just one piece of the puzzle.

On the flip side, some small beans, like peaberries (a natural mutation where only one round bean forms in a cherry), are prized for their concentrated flavors. So, small doesn’t always mean lesser—it can mean special.

Size and Roasting: A Delicate Dance

Bean size does play a crucial role in roasting. When beans of different sizes are roasted together, the results can be... well, a bit chaotic. Smaller beans roast faster, while larger ones take longer. This mismatch can lead to uneven results: burnt small beans or underdeveloped large ones.

To avoid this, beans are sorted by size before roasting. If you’ve ever bought a bag of coffee with a mix of bean sizes, chances are it came from a roastery that blends after roasting.

The Screening Process: Sorting by Size

Coffee beans are sorted using sieves with different-sized holes. These sizes are measured in increments of 1/64th of an inch. For example:

Size 8: Beans about 3.2 mm in diameter.

Size 20: Beans nearly 8 mm across.

Most commercial coffee falls between sizes 15 and 18. However, exact size categories can vary by region. For instance, in Central America, you might hear terms like "Caracolillo" or "Superior," while African coffee grades often use labels like "AA" or "TT."

The Peaberry Exception

Let’s not forget the peaberry. This small, round bean packs a flavorful punch. While typically a mutation (about 10% of all coffee cherries), peaberries are often separated by hand, making them rare and sought after. Fans swear they taste fruitier and sweeter than regular beans.

Conclusion: Does Size Really Matter?

In the world of coffee, size isn’t everything. The variety, roasting process, and brewing method have a much bigger impact on taste. While larger beans of the same variety might suggest higher quality, exceptions like peaberries prove that small beans can deliver big flavors.

So, the next time you’re tempted to judge a coffee by its bean size, remember: it’s not about how big the bean is—it’s about how good it tastes. And that’s the only metric that truly matters in your cup.