How Coffee Beans Are Graded by Country and Altitude

Ever wondered why some bags of green coffee beans are labeled AA, SHB, or G1 — and whether those grades mean anything? These aren’t random letters. They’re part of a global system that sorts beans by origin, quality, and processing method. If you’ve ever been confused by what these coffee grading codes actually mean — or why your favorite single origin always seems to come from high-altitude farms — this guide breaks down the real systems used worldwide.

Coffee is graded using three main methods: by altitude (common in Central America), by bean size using screens (like Kenya and Colombia), and by defect count combined with screen size (as in Ethiopia and Brazil). Each system reflects local growing conditions, harvest practices, and market priorities — and all directly impact how your coffee tastes.

1. Altitude-Based Grading: Why Higher Elevation Usually Means Better Coffee

One of the most common ways to grade coffee is by the altitude at which it’s grown. The general rule: higher altitude slows down bean development, leading to denser, more complex beans with better flavor potential. That’s why many producing countries use altitude bands to define quality tiers.

Countries like Guatemala, Honduras, El Salvador, and Mexico grade beans this way. In Guatemala, for example:

• SHB (Strictly Hard Bean): grown above 1,350 m
• HB (Hard Bean): 1,200–1,400 m
• SH (Semi Hard Bean): around 1,000–1,200 m
• EPW (Extra Prime Washed), PW (Prime Washed), EGW (Extra Good Washed), GW (Good Washed): grown at progressively lower altitudes, down to 600 m or less

These altitude-driven grades are widely used in Central America, where cooler temperatures at elevation help develop sugars and acids slowly, resulting in more vibrant and stable beans for roasting.

2. Screen Size (Sieve) Grading: Bigger Beans, But Not Always Better

Another major grading system uses mesh screens to sort beans by physical size. The size is measured in 1/64-inch increments — so a No. 17 sieve has holes 17/64 inches (about 6.75 mm) wide. The larger the number, the bigger the bean.

Why does size matter? Bigger, denser beans often roast more evenly and can express more complex flavors — though small beans (like Ethiopia’s renowned heirloom varieties) can still be outstanding. This system is especially common in East Africa and parts of South America.

Notable examples include:

• Kenya: Uses AA++ (screen size over 18/64 inch, >7.15 mm), AA+, AA, and AB. AA++ is their highest grade.
• Colombia: Divides beans into Supremo (mostly 17/64 inch and up) and Excelso (mostly 14/16, with up to 11% allowance of smaller beans).
• Tanzania and other countries also use similar sieve systems, often alongside other criteria.

For round beans (peaberry), different sieve sizes apply — typically 8 to 12.

3. Defect Rate + Screen Size: The Most Detailed Grading Systems

The most precise grading methods factor in both the number of defective beans and screen size. Defects — like broken, black, sour, or insect-damaged beans — can ruin cup quality, so their count is tightly controlled in specialty-grade coffees.

Countries using this combined approach include:

• Jamaica: Considers altitude, region, sieve size, and defects, allowing a maximum 4% defect rate across all grades.
• Brazil: As the world’s largest producer, Brazil uses multiple methods — including sieve size, defect count, and cupping tests. Their six-tier cup quality system ranges from Strictly Soft (excellent balance) to Rioy (harsh iodine notes from soil contact near Rio de Janeiro).
• Ethiopia: Often includes processing method as part of the grade, and typically evaluates beans based on a mix of cleanliness, bean shape, and defect counts.

Brazil’s unique cupping test involves roasting, grinding, and brewing samples, then assessing them for acidity, sweetness, body, and off-flavors. This functional approach helps ensure exported lots meet buyer expectations despite the country’s vast and varied production.

How Countries Choose Their Grading Method

There’s no universal coffee grading standard. Instead, each producing country uses a method that fits its geography, farming practices, and market focus. Here’s how location influences the system:

• Near the equator (high altitude by default): Countries like Colombia, Tanzania, and Kenya usually grade by screen size. They grow at elevation regardless, so altitude isn’t the main variable.
• Middle elevations, washed processing: In Mexico, Guatemala, Honduras, Costa Rica, and El Salvador, altitude determines grade due to distinct growing zones.
• Dry-processed, hand-picked regions: Places like Ethiopia and Peru, where dry processing leads to more defects, rely more on defect counting.
• Mass production or mixed methods: Brazil, Indonesia, Vietnam, and Jamaica typically grade by both screen size and defect rates.

These choices reflect each country’s reality: how beans are farmed, harvested, processed, and prepared for export. The result is a global patchwork of systems — all designed to signal quality before the beans even reach a roaster.

Frequently Asked Questions

What does SHB mean on a coffee bag?

SHB stands for “Strictly Hard Bean,” a Guatemalan grade for coffee grown above 1,350 meters. These high-elevation beans develop slowly, creating denser, more flavorful beans favored for specialty roasting. Similar terms include HB (Hard Bean, 1,200–1,400 m) and SH (Semi Hard Bean, around 1,000–1,200 m).

Why are Kenyan beans labeled AA or AB?

Kenyan coffee uses a screen size grading system where AA beans are the largest (passing through 18/64-inch or larger sieves), followed by AB (smaller size). AA++ is their top grade, indicating both large bean size and high cup quality, often sourced from high-altitude farms.

Does Brazil grade coffee by taste?

Yes. In addition to sieve size and defect counting, Brazil uses a cupping test to grade coffee. The six-tier system includes grades like Strictly Soft (excellent balance), Soft, and Softish (good), down to Hard, Rio, and Rioy (unpleasant iodine or harsh flavors caused by soil contact during harvest).

Is a higher screen number always better?

Not necessarily. While larger beans (higher screen numbers) often roast more evenly and can have more complex flavors, small beans — such as Ethiopia’s native varieties — can still produce exceptional cups. Size is just one factor among many in coffee grading.

Why do some countries use defect counts in grading?

Defective beans — broken, black, sour, or insect-damaged — negatively affect flavor and roast quality. Countries like Ethiopia, Jamaica, and Brazil set strict limits on how many defective beans are allowed in each grade to ensure consistency and cup quality, especially for export.

Recommended FrontStreet Beans for Altitude & Grading Insights

Explore how altitude and grading shape flavor with these FrontStreet offerings: Kenya Little Tomato (bright acidity, blackcurrant, winey notes from high-altitude SL28/SL34), Brazil Queen Manor (sweet, creamy profile from yellow bourbon grown at lower altitudes), and Jamaica Blue Mountain No.1 (balanced, nutty, and smooth — a classic high-elevation washed coffee). Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.