Green Coffee

Foundational Quality Control Before a single bean enters a roaster, it must pass a rigorous physical examination. Grading is the silent gatekeeper of coffee quality, ensuring that the raw product meets professional standards and contractual obligations. This process provides a blueprint for roasters, allowing them to anticipate how the coffee will react to heat and chemical transformation. By mastering these physical parameters, we honor the hard work of the producers at origin and protect the integrity of the final cup. Essential Tools of the Trade To perform a professional grade, you need specific precision instruments. You must have a **moisture and density meter** to capture internal bean data. For physical sizing, a set of **grading screens**—metal plates with standardized circular perforations—is required. Finally, a large **black mat** provides the necessary contrast to visually identify defects in a standard 350-gram sample. Step-by-Step Grading Protocol 1. **Analyze Moisture and Density**: Measure the moisture content immediately. You are looking for a sweet spot between 9% and 12%. Anything outside this range signals potential roasting instability or poor drying practices at the farm. 2. **Execute Screen Grading**: Pour your sample into the screens and shake. This separates beans by size. A lot typically passes if at least 95% of the beans remain on the target screen size. 3. **Perform Defect Sorting**: Spread 350 grams of green coffee across your black mat. Scrutinize every bean for physical anomalies. This step determines the final grade and confirms the coffee matches the agreed-upon quality from the supplier. Troubleshooting Common Issues If moisture levels exceed 12%, the coffee risks mold and will resist consistent heat absorption during roasting. Conversely, coffee under 9% may have aged poorly or dried too quickly, leading to a flat, woody flavor profile. When density is low, roasters must adjust their heat curves to avoid scorching the more fragile cellular structure of the bean. The Outcome of Professional Grading A successful grading session results in complete transparency between the trader, the origin, and the roaster. It eliminates surprises in the roasting drum and ensures that the flavor potential you paid for is actually present in the raw material.