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

Ever wondered why some coffees cost more or taste better? Much of that comes down to how the raw beans were graded before export. Different coffee-growing nations use specific methods to rank their beans—based on where they’re grown, how big they are, and how many flaws they carry. These grading systems shape everything from roast potential to flavor consistency. Here’s how the world sorts its green coffee.

The three most common ways to grade green coffee beans are by altitude, bean size (using screens), and the number of defects—each method reflecting local growing conditions and market priorities. Altitude often signals density and sweetness, larger beans tend to have more even roasts, and fewer defects mean cleaner cups. No single system fits all, but together they help roasters find quality beans.

1. Altitude-Based Grading

Higher elevations typically produce denser, slower-maturing coffee cherries. The cooler temperatures slow growth, allowing more complex sugars and acids to develop. These beans are often more stable during roasting and offer richer flavors. Countries like Guatemala, Honduras, El Salvador, and Mexico grade beans by altitude. In Guatemala, for example:

• SHB (Strictly Hard Bean): 1,350m+
• HB (Hard Bean): 1,200–1,400m
• SH (Semi Hard Bean): ~1,000m
• EPW (Extra Prime Washed): 800–1,000m
• PW (Prime Washed): 600–800m
• EGW (Extra Good Washed): 600–800m
• GW (Good Washed): below 600m

Other terms include SHB (1,350m+), HB (1,200–1,400m), SH (around 1,000m), and lower tiers for beans grown at 600m and below. Altitude isn’t just about height—it’s about what happens to the bean inside the fruit.

2. Screen Size (Sieve) Grading

This method sorts beans by physical diameter using mesh screens with holes sized in 1/64-inch increments. The higher the screen number, the larger the bean. Bigger beans often roast more evenly and have a more uniform appearance, though small beans (like Ethiopia’s or Yunnan’s) can still shine in flavor. Key examples:

• Kenya: AA++ (screen 18+; >7.15mm), followed by AA+, AA, AB
• Colombia: Supremo (screen >17), Excelso (screen 15–16.5)
• Ethiopia (peaberries): 8–12 screen sizes used

For flat beans, Kenya’s grading is especially detailed. Colombia simplifies to Supremo and Excelso. Peaberries (small, round beans) follow their own size scales, typically 8–12 screens. Size affects roast quality and market appeal—but not always flavor.

3. Defects + Screen Size Grading

Defects—broken, black, sour, or insect-damaged beans—ruin cup quality. Many producing nations now emphasize defect counts alongside screen size to ensure cleaner lots. Countries like Jamaica, Brazil, and Ethiopia lead here. Examples:

• Jamaica Blue Mountain No.1: screen 17–18, <2% defects, from 1,700m+
• Brazil: Uses defect counts (e.g., Type 2 allows 4–12 defects per 300g), screen size, and cupping tests (six grades from ‘Strictly Soft’ to ‘Rioy’)
• Ethiopia: Graded by defects per 300g (e.g., Grade 1 = 0–3 defects; Grade 8 = over 340 = substandard)

Brazil combines multiple methods, including a unique cupping step where roasted beans are brewed and assessed for aroma and taste. Defect control is critical for specialty-grade lots, and this method helps ensure consistency.

Regional Grading Standards at a Glance

Different origins have unique systems. Here’s a snapshot:

• Kenya: AA++ (screen 18+), AA+, AA (screens 17–18), AB (screens 15–16), C, E, PB (peaberry)
• Ethiopia: Graded 1–8 based on defects per 300g (Grade 1 = 0–3; Grade 8 = over 340)
• Colombia: Supremo (>17 screen), Excelso (15–16.5 screen), UGQ (12–14 screen)
• Brazil: Numeric types (Type 2 to 6) based on defects (e.g., Type 2 = 4–12 defects) and cup quality grades
• Guatemala: SHB (1,350m+), HB (1,200–1,400m), SH (1,000–1,350m), down to GW (below 600m)
• El Salvador: SHG (>1,200m), HG (900–1,200m), CS (500–900m), plus naturals like Corriente, Superior, Caracol
• Hawaii Kona: Extra Fancy (screen 19, ≤10 defects), Fancy (screen 18, ≤16), Prime (≤25 defects), Caracoli No.1 (screen 10, ≤20)
• Jamaica: Blue Mountain Grade I (screen 18), II (17), III (16); Peaberry also graded
• Indonesia: Grades 1–6 based on defects in 300g (Grade 1 = 11 defects; Grade 6 = 151–225)

Some origins, like Ethiopia and Rwanda, also factor processing method into grading. And global attention to quality has made systems like COE (Cup of Excellence) more influential.

Frequently Asked Questions

What does SHB mean on coffee beans?

SHB stands for Strictly Hard Bean, a grade given to coffee grown at altitudes above 1,350 meters, typically in Guatemala. These beans are denser due to slower growth at high elevation, often leading to sweeter, more complex flavors when roasted.

Why are larger coffee beans considered better?

Larger beans (e.g., screen 17–18 or higher) usually roast more evenly and have a more consistent appearance. While size doesn’t guarantee quality, it often correlates with uniformity and marketability, especially in specialty lots.

How do defects affect coffee quality?

Defects—such as broken, black, sour, or insect-damaged beans—can ruin the flavor of an entire lot. Grading systems that count defects (e.g., Jamaica’s <2% allowance for Blue Mountain No.1) help ensure cleaner, higher-quality cups.

Do all countries grade coffee the same way?

No. Countries use different methods based on their climate, terrain, and market needs. Common systems include altitude grading (e.g., Guatemala), screen size (e.g., Kenya, Colombia), and defect counting (e.g., Brazil, Ethiopia).

What is the role of screen size in coffee grading?

Screen size refers to the physical diameter of green beans, measured using mesh sieves. Higher screen numbers (e.g., 18) mean larger beans, which often roast more evenly and are associated with premium lots, especially in Kenya and Colombia.

Why does altitude matter in coffee grading?

Higher-altitude coffee grows more slowly in cooler temperatures, allowing better development of sugars and acids. This usually results in denser beans with more complex flavors, which is why altitude is a key grading factor in Central and South America.

FrontStreet Beans for Altitude & Processing Fans

Explore FrontStreet’s Ethiopia Guji Huika (Yirgacheffe region, washed, bright citrus and floral notes) and Kenya Gakuyuni AB (medium-high acidity, blackcurrant and stone fruit). For a washed Colombian example, try FrontStreet’s Huila Supremo (nutty with citrus brightness). All highlight how origin, altitude, and processing shape green bean grade and cup profile. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.