How Coffee Beans Are Graded by Country and Altitude

Ever wondered why some bags of coffee boast ‘SHB’ or ‘AA’ on the label—and what those letters really mean for flavor? The truth is, there’s no universal coffee bean grading system. Each producing country sets its own rules, leading to a confusing patchwork of classifications. For buyers and roasters, understanding these systems is the key to predicting cup quality before brewing.

In short: altitude, bean size, and defect counts determine a coffee’s grade. High-altitude beans (like SHB at 1350+ meters), larger screen sizes (AA often means 7.2mm+), and low defect rates (like Brazil’s Strictly Soft) signal higher quality—but the exact criteria vary by origin.

Why Altitude Matters in Coffee Grading

Higher elevations slow coffee cherry ripening, producing denser, more complex beans. This is why most Central American countries grade coffee primarily by altitude. The cooler temperatures at elevation allow cherries to mature fully, resulting in beans with better expansion during roasting and fewer defects.

• Guatemala: SHB (Strictly Hard Bean) = 1350+ meters
• Mexico: SHG (Strictly High Grown) = 1700+ meters
• El Salvador & Honduras: SHG = 1200+ meters

These regions grow coffee on mountain slopes, often handpicked to ensure only ripe cherries are harvested. The labor-intensive process reduces contamination from underripe or damaged beans, contributing to higher-quality lots.

Screen Size: Grading by Bean Dimensions

Countries like Kenya, Tanzania, and Colombia use mesh sieves to sort beans by physical size—a method known as screen size grading. The size of the holes, measured in 1/64-inch increments, determines the sieve number. Larger beans often correlate with higher quality, as they tend to have more uniform development.

• Tanzania: AA grade = 18+ sieve (≥7.14mm)
• Kenya: AA grade = ≥7.2mm sieve
• Colombia: Supremo = 17+ sieve; Excelso = 14/16 mix (16mm with 11% 14mm beans)

The sieve system ensures consistency in bean size, which is crucial for even roasting. Uniform beans roast more predictably, enhancing flavor balance in the cup.

Brazil’s Unique Three-Part Grading System

Brazil, the world’s largest coffee producer, combines multiple factors: defect count, screen size, and cup quality. Its grading system is unmatched elsewhere, using a numerical defect scale, sieve number, and flavor descriptor.

For example, a lot labeled ‘Brazil Santos NO.2, 19 sieve, Strictly Soft’ breaks down as:

• Brazil = origin
• Santos = export port
• NO.2 = defect grade (NO.2 is highest, NO.8 is minimum for export)
• 19 sieve = bean size (Brazil uses 12–20; higher numbers = larger beans; flat beans only)
• Strictly Soft = cup quality (highest rating in Brazil’s flavor classification)

This three-pronged approach offers a detailed snapshot of the lot’s potential, though it’s rarely used outside Brazil.

Other Grading Methods: Terroir and Cultivation Class

Beyond the big three, some regions use additional criteria. Jamaica, for instance, grades coffee based on cultivation area, reflecting how terroir influences flavor. While not as widely adopted, these methods highlight the role of environment in coffee quality.

Frequently Asked Questions

What does SHB mean on a coffee bag?

SHB stands for ‘Strictly Hard Bean,’ a Guatemalan grade for beans grown at 1350 meters or higher. The term indicates denser beans due to slower ripening at altitude, often correlating with higher cup quality.

What is the difference between AA and AB coffee grades?

AA and AB are size-based grades, common in Kenya and Tanzania. AA typically refers to the largest beans (≥7.2mm sieve), while AB is slightly smaller. AA beans are often associated with higher quality, though flavor also depends on processing and origin.

How does Brazil grade its coffee beans?

Brazil uses a three-part system: defect count (NO.1–NO.8, with NO.2 being highest), screen size (12–20, higher is larger), and cup quality (e.g., ‘Strictly Soft’ for the best flavor). For example, ‘Santos NO.2, 19 sieve, Strictly Soft’ meets top standards for defects, size, and taste.

Why is altitude important for coffee quality?

Higher altitudes slow cherry ripening, producing denser beans with more complex flavors. Most Central American countries grade coffee primarily by altitude because of this quality link.

What is a coffee sieve number?

A sieve number refers to the size of the holes in a mesh used to sort coffee beans. Measured in 1/64-inch increments (e.g., 17 sieve = 17/64 inch or 6.75mm), larger numbers indicate bigger beans, which often roast more evenly and consistently.

Do all countries use the same coffee grading system?

No. Each major coffee-producing country has its own grading criteria, such as altitude (Central America), screen size (Kenya, Colombia), or a combination (Brazil). There is no universal standard, which can make buying green coffee more complex.

FrontStreet Beans for Altitude & Quality Lovers

Explore FrontStreet Coffee’s Ethiopia Yirgacheffe for bright, floral notes from high-altitude growing (1800–2000m), or try Guatemala Antigua SHB—dense, chocolatey beans grown at 1500+ meters. Both reflect the quality tied to elevation and careful processing. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.