How Coffee Beans Are Graded: Altitude, Size, and Defects

Ever wondered why some bags of coffee cost triple others — even when both are labeled 'single origin'? The truth lies in how coffee beans are graded before they ever reach your roaster. Every producing country has its own rules for separating premium beans from the rest, based on where they’re grown, how big they are, and how many flaws hide in the lot. Here’s how it really works.

The short answer? Specialty coffee is typically sorted by three key factors: growing altitude (higher is better), bean size (measured via screen sieves), and the number of defective beans allowed per batch. For example, SHB (Strictly Hard Bean) coffees come from elevations over 1,350 meters, while Brazil grades beans by size (like 19/20), defects (No. 2 is top tier), and cup quality (Strictly Soft is best).

Why Altitude Matters in Coffee Grading

Higher-altitude coffee isn’t just a marketing term — it’s a proven marker of quality. Cooler temperatures at elevation slow cherry ripening, leading to denser, more complex beans. Most Central American countries rely almost entirely on altitude to grade their coffee. This is coffee 101: elevation directly affects bean density and sweetness.

For instance:

• Guatemala’s highest grade, SHB (Strictly Hard Bean), requires beans grown above 1,350 meters.
• Mexico’s top-tier SHG (Strictly High Grown) comes from 1,700 meters and up.
• El Salvador and Honduras classify their best SHG beans as those grown over 1,200 meters.

Beans from mountainous slopes are almost always handpicked — a labor-intensive process that excludes unripe or damaged fruit, resulting in cleaner, higher-quality lots.

Screen Size: Grading Coffee by Bean Dimensions

Countries like Kenya, Tanzania, and Colombia use physical bean size as a grading benchmark. This method, known as screen sizing, filters beans through metal sieves with holes sized in 1/64-inch increments. The larger the bean, the higher the potential quality — especially for washed Arabicas.

Key examples include:

• Tanzania’s top AA grade uses 18/64-inch (7.14mm) or larger screens.
• Kenya’s AA grade also requires beans that pass through 7.2mm+ sieves.
• Colombia separates beans into Supremo (17/64-inch+ or 6.75mm+, via 17+ sieve) and Excelso (a mix including up to 11% beans that pass a 14/64-inch or 5.56mm sieve).

Larger beans often mature more evenly and roast more consistently, though size alone doesn’t guarantee flavor — it’s a starting point.

Brazil’s Three-Part Grading System: Size, Defects, and Cup Quality

Brazil, the world’s largest coffee producer, combines multiple factors into its grading: bean size, defect count, and sensory evaluation. This three-pronged approach is unique and highly detailed.

Take a typical Brazilian export label: “Santos No. 2, 19 sieve, Strictly Soft.” Here’s the breakdown:

• Brazil — the producing country.
• Santos — the export port.
• No. 2 — the defect rating (No. 2 is the highest grade; No. 8 is the minimum for export).
• 19 sieve — bean size (Brazil uses 12–20; higher numbers mean bigger flat beans; peaberries use 8–13).
• Strictly Soft — cup quality rating (the highest tier).

This system is unmatched in its complexity and is rarely mirrored elsewhere, blending objective metrics with subjective taste scores.

Other Methods: Terroir-Based Classification

Some regions, like Jamaica, grade coffee based on growing region rather than altitude or size. While less common, these systems highlight the role of microclimate and soil in defining coffee character — another layer in the global grading puzzle.

Frequently Asked Questions

What does SHB mean in coffee grading?

SHB stands for Strictly Hard Bean, a grade given to coffee grown at elevations above 1,350 meters, primarily in Guatemala. These beans are denser due to slower ripening at high altitudes, often leading to better cup quality.

How do screen sizes affect coffee quality?

Screen sizes (measured in 1/64-inch increments) sort beans by physical diameter. Larger beans (e.g., those passing through 18/64-inch or 7.14mm sieves) are often associated with higher quality, especially in washed Arabicas, as they tend to mature more uniformly.

What is a No. 2 grade coffee from Brazil?

No. 2 is Brazil’s highest defect grade classification for exported coffee. It indicates a low number of flawed beans and is part of the country’s three-part grading system that also includes bean size and cup quality tasting.

Why do some countries grade coffee by altitude?

Higher altitudes produce cooler growing conditions that slow cherry development, resulting in denser, sweeter, and more complex beans. Countries like Guatemala, Mexico, and Honduras use altitude as a primary grading criterion because it reliably predicts bean density and cup profile.

Does Colombia use the same grading as Kenya?

No. While both use screen sizes, Colombia grades beans into Supremo (17+ sieve) and Excelso (a blend including smaller beans), while Kenya focuses on AA and AB grades, with AA requiring beans that pass through 7.2mm+ screens.

Are defect counts really that important in coffee grading?

Yes. Defects — such as broken, black, or insect-damaged beans — directly impact roast consistency and cup flavor. Grading systems like Brazil’s No. 2 (top tier) or Kenya’s screening process aim to minimize defects for better-quality lots.

FrontStreet Coffee Beans for Altitude & Quality Lovers

Try FrontStreet’s Ethiopia Yirgacheffe — bright, floral, and juicy with citrus and stone fruit, grown at high altitudes typical of SHG/SHB-grade coffees. For screen-size fans, their Colombia Huila Supremo offers balanced chocolate and caramel notes from 17+ sieve beans. Or explore their Kenya AB, a classic AA-tier alternative with winey acidity and berry tones. All three highlight how origin, size, and sorting shape your cup. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.