How Coffee Quality Is Graded Around the World

Every country that produces or consumes coffee in significant quantities has developed systems for evaluating and classifying its quality. These grading systems — some centuries old, others recently formalized — attempt to reduce the subjective complexity of coffee quality into categories, numbers, or designations that facilitate trade, set price expectations, and communicate quality information between participants who may be separated by thousands of miles and who may never taste the same cup. Understanding how coffee is graded around the world reveals the different priorities that different markets and traditions bring to the question of what constitutes quality — and why a coffee that is considered excellent in one system may be graded differently in another.

Why Grading Exists

Coffee grading serves a fundamental commercial purpose: it enables buyers and sellers to negotiate transactions based on shared quality expectations. Without grading, every transaction would require the buyer to physically inspect and taste the coffee before purchase — a practical impossibility in a global market where coffee travels from dozens of producing countries to hundreds of consuming ones. Grading systems create a common language that allows a buyer in Hamburg to purchase coffee from a seller in Addis Ababa with reasonable confidence about what will arrive.

Grading also serves quality incentive functions. When grading systems link quality classifications to pricing — higher grades commanding higher prices — they create economic signals that encourage producers to invest in the agricultural and processing practices that improve quality. Conversely, when grading systems fail to differentiate effectively, they can trap producers in a commodity paradigm where quality investment goes unrewarded.

Physical Grading: Defect Counts and Bean Size

The oldest and most widespread approach to coffee grading evaluates physical characteristics of the green bean: size, density, color, and the number and type of defects present in a sample. Physical grading can be performed without tasting the coffee — it requires only visual inspection, screens for size sorting, and standardized defect classification tables.

Defect Classification

Green coffee defects fall into two broad categories. Primary defects — full black beans, full sour beans, dried cherries, and foreign material — are considered severe because they produce unmistakable off-flavors in the cup. Secondary defects — partial blacks, partial sours, broken beans, shells, and insect-damaged beans — are less severe individually but can compromise cup quality when present in significant numbers. Different grading systems weight these defects differently, but all recognize the principle that the number and severity of defects present in a sample inversely correlate with the sample’s quality potential.

Screen Size

Bean size, measured by passing samples through screens with progressively smaller perforations, serves as a rough quality proxy. Larger beans — typically grown at higher altitudes where slower maturation allows greater density and sugar accumulation — correlate loosely with better cup quality. Screen size classifications vary by country: Colombian Supremo designates beans retained on a screen size of seventeen, while Kenyan AA designates the same screen size using different nomenclature. The altitude-quality relationship that underlies these size correlations is explored in our article on the influence of altitude on coffee bean development.

Country-Specific Grading Systems

Ethiopia

Ethiopia, the birthplace of Arabica coffee, grades its coffee on a scale of one to nine, with grades one through three reserved for specialty export quality. The system evaluates both physical defects and cup quality through standardized cupping, reflecting Ethiopia’s recognition that physical appearance alone does not capture the full quality picture. Ethiopian grades also differentiate between washed and natural processing, acknowledging the distinct quality characteristics that each method produces.

Brazil

Brazil, the world’s largest producer, uses a complex grading system that classifies coffee by bean type, screen size, cup quality, and the number of defects per three-hundred-gram sample. The defect count system assigns numerical values to different defect types and sums them to produce a total that determines the grade. Brazilian Santos Grade 2, for example, permits a maximum of four full defects per sample. The system’s granularity reflects the enormous volume and diversity of Brazilian production, which requires precise classification to manage commercial transactions at scale.

Colombia

Colombia classifies its coffee primarily by bean size and defect count. Supremo — the highest commercial grade — requires beans retained on a seventeen-screen with minimal defects. Excelso permits slightly smaller beans. Colombia’s grading system reflects the country’s longstanding focus on producing and marketing consistently high-quality washed Arabica, and its relatively simple classification structure communicates that quality focus efficiently to international buyers.

Kenya

Kenya’s grading system classifies beans by size — AA, AB, PB, C, and so on — with AA designating the largest beans and commanding the highest prices at auction. The Kenyan system is notable for its auction-based pricing mechanism, which allows quality to be rewarded through competitive bidding rather than predetermined price schedules. This market structure has incentivized Kenyan producers to invest in quality, contributing to Kenya’s reputation for producing some of the world’s most distinctive and sought-after coffees.

The SCA Cupping Protocol

The Specialty Coffee Association has established the most widely used sensory grading protocol in the specialty market. The SCA cupping protocol evaluates coffee across ten attributes — fragrance and aroma, flavor, aftertaste, acidity, body, balance, uniformity, clean cup, sweetness, and overall impression — each scored on a scale, with the total determining the coffee’s classification. Coffees scoring eighty points or above qualify as specialty grade; below eighty, they are classified as commercial grade.

The SCA protocol’s strength is its attempt to standardize subjective sensory evaluation through defined vocabulary, calibrated references, and trained evaluators called Q Graders. Its limitation is that sensory evaluation inherently involves human judgment, and scores can vary between evaluators, between sessions, and between the same evaluator on different days. Despite these limitations, the SCA system has become the global lingua franca of specialty coffee quality assessment and the primary mechanism through which quality-based pricing operates in the specialty market. The broader ecosystem of certifications and quality indicators that consumers encounter is examined in our article on understanding coffee certifications and quality scores.

Cup of Excellence

The Cup of Excellence program represents the pinnacle of competitive coffee quality evaluation. Operated by the Alliance for Coffee Excellence, the program conducts rigorous multi-round cupping evaluations in participating producing countries, identifying the highest-scoring lots and selling them through international auction. Coffees that win Cup of Excellence designations regularly sell for prices many times the commodity market rate, and the program has been instrumental in demonstrating that exceptional quality can command exceptional prices when properly identified and marketed.

The Cup of Excellence model has influenced quality-focused production in every country where it operates, creating aspirational targets for producers and transparent quality benchmarks for buyers. It has also revealed the extraordinary quality potential of origins previously underrepresented in the specialty market, as explored in our discussion of what makes specialty coffee different from commercial coffee.

Limitations and Ongoing Debates

No grading system perfectly captures coffee quality. Physical grading misses flavor defects that are invisible to the eye. Sensory grading introduces subjectivity that can vary between evaluators. Country-specific systems reflect local priorities that may not translate to international markets. And all systems face the fundamental challenge that quality is contextual — a coffee that is extraordinary as a filter brew may be unremarkable as an espresso, and a coffee that delights one palate may leave another indifferent.

The ongoing evolution of coffee grading reflects the industry’s attempt to refine its quality language in response to growing consumer sophistication and the specialty market’s demand for more precise, more transparent, and more equitable quality assessment. Whether through technological innovation, improved sensory methodology, or more inclusive frameworks that incorporate producer perspectives alongside buyer preferences, the grading systems of the future will continue to shape how quality is defined, rewarded, and communicated in the global coffee trade.

Conclusion

Coffee grading is the infrastructure of quality communication in a global industry. From defect counts and screen sizes to cupping scores and competition rankings, grading systems translate the complex, multidimensional reality of coffee quality into standardized categories that facilitate trade, incentivize investment, and help consumers navigate an increasingly diverse marketplace. Understanding these systems — their logic, their limitations, and their consequences — enriches the coffee experience by revealing the invisible framework that determines which coffees reach which markets, at what prices, and with what expectations attached.