How Coffee Beans Are Graded by Size and Altitude

When you buy specialty coffee, have you ever wondered why some beans cost more or roast differently? One key reason is how those green beans were sorted and classified before export—by both physical size and the altitude where they grew. These grading systems affect roast profiles, flavor consistency, and even price.

In short: Coffee beans are graded by mesh size from 8 (smallest) to 29+ (largest), and by altitude into seven grades from G.W (~2000m) up to S.H.B (4500m+). Bigger beans and higher-grown lots are typically more uniform and valued higher in the specialty market.

Why Grade Coffee Beans?

Green coffee grading exists for two main reasons: to improve roast quality and to reflect bean quality in pricing. Sorting beans by size ensures even roasting, since uniformly sized beans absorb heat more consistently. Grading by altitude helps identify beans grown in cooler conditions, which often develop more complex flavors. Together, these systems help roasters choose beans that roast predictably and taste better.

Grading by Screen Size (Mesh Number)

Coffee beans are commonly graded by passing them through metal screens with different-sized holes. The screen number refers to the number of openings per linear inch—so a higher number means bigger holes and larger beans that can pass through. This system is straightforward: the larger the mesh number, the larger the bean that can pass.

• Beans are sized using numbers ranging from 8 to 29 and above.
• Smaller beans fall in the 8–13 range; larger beans are 18–29 or higher.
• Flat beans (the common bean type) usually measure between 12 and 29.
• Peaberry beans (smaller, rounded beans) typically range from 8 to 13.
• Example: An SC-19 grade means the beans passed through a size 19 screen—they are considered large.

The goal is to achieve uniform bean size, which makes roasting more predictable and improves cup consistency. Larger beans are not inherently better tasting, but they often roast more evenly when sorted properly.

Grading by Growing Altitude

Coffee is also graded based on the elevation at which it’s grown. Higher altitudes generally mean slower ripening, which leads to denser beans with more complex flavors. Most producing countries use altitude as a key part of their grading scale. The following table outlines a common seven-tiered altitude classification used in some regions:

As a rule, the higher the altitude (and grade), the more potential for complex, vibrant cup profiles—but also the greater the farming challenge and cost. That’s why beans grown above 4000 meters, like S.H.B, not only taste different but also command higher prices due to limited supply and shipping difficulty.

What These Grades Achieve

The two grading systems—size and altitude—work together to create more predictable and valuable green coffee. Sorting by size improves roast uniformity, while altitude-based grading highlights beans with optimal growing conditions for specialty qualities. Together, they support better quality control, more consistent roasting, and fairer pricing based on measurable attributes.

Frequently Asked Questions

What does SC-19 mean for coffee beans?

SC-19 means the coffee beans passed through a size 19 mesh screen. It indicates a relatively large flat bean, with 19 referring to the number of openings per inch on the grading sieve. Larger numbers mean larger beans.

Do larger coffee beans taste better?

Larger beans don’t automatically taste better, but they often roast more evenly when sorted by size. Uniform size improves consistency in roasting and extraction, which can lead to a more balanced cup.

Why are high-altitude coffee beans considered better?

Higher-altitude coffee beans usually grow more slowly, leading to denser beans with concentrated sugars and acids. This often results in more complex and vibrant flavors, which is why altitude is a key factor in specialty grading.

What is peaberry coffee and how is it graded?

Peaberry beans are small, rounded beans that form when only one seed develops inside a coffee cherry instead of two. They usually fall in the 8 to 13 screen size range and are often separated and graded separately due to their distinct shape and sometimes unique cup profile.

What altitude is considered high for coffee growing?

In coffee grading systems, altitudes above 3000 meters are generally considered high, with grades like S.H.B starting at 4500 meters. Beans grown at these heights are often denser and more sought-after in specialty markets.

How does bean grading affect roasting?

Grading ensures beans are uniform in size or grown under consistent conditions. This allows roasters to apply more precise roast profiles, improving flavor development and reducing inconsistencies in the final cup.

FrontStreet Coffee Beans Ideal for Size & Altitude Exploration

Try FrontStreet Coffee’s Ethiopia Huakui for a high-altitude Ethiopian experience with bright citrus and floral notes, grown at elevations matching the E.P.W to S.H.B grades. For a denser, balanced cup, their Kenya Little Tomato offers tart berry and winey acidity typical of high-grown beans. Or explore Panama Huacai, a complex, high-altitude lot with notes of tropical fruit and honey—ideal for seeing how elevation shapes flavor. All three highlight why size and altitude matter. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.