Green coffee quality control is a technical process requiring absolute precision, adhering to the Specialty Coffee Association (SCA) rules. It is the 'common language' between producers, traders, and professional roasters worldwide to determine the true value of coffee beans.
Physical grading is performed on a 350g green coffee sample. Defects are divided into two main groups: Primary Defects and Secondary Defects. For 'Specialty' coffee, no primary defects are allowed in the sample.
| Defect type | Example | Exchange factor |
|---|---|---|
| Primary | Full Black, Sour Bean | 1 hạt = 1 lỗi |
| Secondary | Insect damage, chipped | 5 hạt = 1 lỗi |
Ideal moisture for export green coffee ranges from 10% to 12%. If moisture exceeds 12%, beans are prone to mold and rapid flavor loss. Beyond moisture, 'Water Activity' (aW) below 0.6 is the safety standard for long-term storage.
Density is another crucial metric. High-density beans typically come from high altitudes, are more solid, and can withstand higher heat during roasting.
Cupping is the final and most important step. SCA protocol specifies a ratio of 8.25g coffee per 150ml water at 92-94°C. Experts evaluate 10 flavor attributes on a 100-point scale.
Before being containerized for export, coffee samples must undergo lab testing for: variety identification, bean size (Screen 16/18), and specifically chemical residues according to importing country standards.
Quality control is not just a technical barrier but a tool to protect brand value. A robust QC system helps businesses maintain consistency and build long-term trust with partners.