Coffee Roasting and Cupping

Roast level reflects the degree of Maillard reaction (browning, aroma development) and caramelization (sweetness, body). Light roasts (ending before or at first crack, ~195-205°C bean temp) retain acidity and origin flavor (floral, fruity notes dominate); Maillard is incomplete, so flavors remain bright. American roast (just after first crack, ~205-210°C) balances acid and sweetness, with moderate body and roasted-chocolate notes. French roast (second crack, ~220-230°C) has low acidity, dark caramel/bitter notes, and heavy body; Maillard is complete and melanoidin (browning polymer) dominates. The chemistry: Maillard peaks around 160-180°C internal bean temp; caramelization (sugar breakdown) peaks around 190-220°C. Light roasts maximize origin character; darker roasts mask origin and emphasize roaster signature (the roasted, smoky notes that define the roaster's house profile).

First crack is the popping sound that occurs around 195-205°C bean temperature as moisture and gases inside beans expand and rupture the seed coat. It marks the onset of rapid Maillard browning and aroma development. Second crack occurs 10-20°C higher (215-230°C) as cell walls continue to break down and oils migrate to the surface. Between first and second crack is the 'development phase' where roasters can extend time to develop sweetness and body or cut short to preserve acid and brightness. Most specialty coffee is roasted in light-to-medium range (first crack to 15-20 seconds post-crack); commercial coffee often pushes to second crack for bold, bitter profiles. The roaster uses cracks as auditory and temporal markers to pace the roast curve and hit consistent targets. Missing or misinterpreting cracks leads to inconsistent roasts.

Green coffee evaluation (cupping green beans, also called 'green cupping') assesses defect level, moisture, density, and aroma. Key defects: full-sours (fermentation damage, high risk for spoilage), black beans (mold, off-flavors), quakers (immature beans with poor roasting), and physical damage (stones, broken beans). Defect count (>5-8 per 300g sample triggers rejection or price discount) is logged. Moisture content (11-12% ideal; below 11% is brittle, above 12% risks mold) is measured with a moisture meter. Density (hard, glassy beans roast more evenly than soft, porous ones) is assessed by hand. Green bean aroma (fresh, clean earthy smell) indicates proper storage and handling; musty or sour aroma flags contamination. Specialty-grade green coffee (SCA score 80+) requires <5 defects/300g, consistent moisture, and clean sensory profile. These metrics predict roasting consistency and final cup quality.

SCA Cupping Protocol (standard since 2015): grind 8.25g coffee medium-fine, brew with 150ml 200°F water, steep 4 minutes, break crust (slurp across spoon loudly to atomize and evaluate aroma/mouthfeel), cool and slurp through hot and cooler phases (until ~60°C), recording flavor, aroma, body, acidity, balance, clean cup, and defects on a 16-point scale. Scores: Aroma (1-9: earthy to complex floral/fruit), Flavor (1-9: clarity, sweetness, origin character vs. roast notes), Aftertaste (1-9: duration and quality of flavor lingering), Acidity (1-9: presence and liveliness), Body (1-9: weight/mouthfeel, light vs. heavy), Balance (1-9: harmony of all components), Uniformity (0-4: consistency across cups), Clean cup (0-8: absence of defects), Overall (1-9: taster's judgment), and Defects (0-4: taints like fermented, sour, baggy). Total score 100-point scale; 80-85 is very good, 85+ is specialty-grade. A panel of 3+ tasters cups the same coffee; scores within ±2-3 points indicate reliable evaluation.

Roast profile (time-temperature curve from charge [bean introduction] to drop [ending]) determines final flavor. A fast roast (8-10 min) develops limited Maillard and emphasizes origin acidity/brightness; a slow roast (12-15 min) develops roast flavors (caramel, chocolate) and body at the cost of origin character. Temperature curve shape also matters: a steep initial rise (drying phase) removes moisture quickly, leaving time for flavor development; a flat curve wastes time in drying and rushes development (risking baked flavors or blocked development). Professional roasters log every roast (charge temp, rise rate, first crack time, development time, drop temp) and correlate curves to cupping scores. Over 500+ roasts, patterns emerge: 'this profile produces bright, acidic cups; this one emphasizes chocolate and body.' Roasters dial in curves for their specific beans and desired cup profile, then repeat them precisely for consistency.

High-altitude coffee (1500+ meters) ripens more slowly, accumulating more sugars and complex amino acids. Result: higher acidity, more floral/fruity notes, and cleaner overall profile. Low-altitude coffee (800-1200m) ripens faster, yielding lower acidity, earthy/nutty notes. Terroir also includes: soil (volcanic soil produces brighter coffee; rich loam produces fuller body), rainfall (adequate moisture = better ripeness; drought stress = thin cup), and shade (shade-grown coffee develops slower, higher complexity; sun-grown is faster, simpler). In a blind cupping, trained palates detect altitude: a Colombian coffee from 1800m tastes noticeably brighter and more floral than a Colombian from 1200m. However, altitude isn't absolute—a masterful roaster can bring out origin character in any altitude coffee if green quality is high and roast profile is precise. Specialty coffee marketing emphasizes altitude and terroir because they correlate with quality and justify premium pricing.

Specialty coffee (defined by SCA as scoring 80+ on 100-point cupping scale) involves rigorous sourcing (single-origin, often single-farm or microlot), traceability (known producer and altitude), careful processing (washed, natural, honey process handled skillfully to avoid defects), meticulous roasting (precise profiles, small batches), and professional evaluation (Q Grader or certified cupper assessment). Commercial coffee is typically bulk-blended, lower-scoring (65-75), with minimal traceability and cupping, optimized for consistency and cost. Specialty coffees cost 2-4x more per pound but command premium prices in retail/café. Specialty roasters often practice direct-trade (buying directly from farms) to ensure quality, fairness, and traceability. The specialty market drives innovation in roasting, cupping, and origin collaboration—it's where craft and commerce intersect.