Every export contract for Vietnamese coffee references a grade — "Robusta Grade 1, Screen 18" or "Arabica Grade 1" — but many first-time buyers aren't sure what those labels actually guarantee. Understanding Vietnam's grading system is essential before you sign a contract, because it determines cup quality, roast consistency, and how much sorting work lands on your side once the container arrives.
The TCVN 4193 Standard
Vietnam's official green coffee standard is TCVN 4193, issued by the national Technical Standards Committee for Coffee and Coffee Products. It replaced older methods that graded coffee mainly on moisture and black/broken bean percentages, and introduced an international-style defect-counting system instead. Under TCVN 4193, green coffee is sorted into Special Grade, and Grades 1 through 5, based on bean size, defect count, and moisture.
For export, the vast majority of specialty-oriented Robusta and Arabica leaving Vietnam is sold as Grade 1, since lower grades rarely meet the cup quality international roasters expect.
Screen Size: What the Numbers Mean
Screen size describes bean dimensions, measured with round-hole screens in increments of 1/64 of an inch. A "Screen 18" bean passes through an 18/64-inch (about 7.1 mm) hole; "Screen 16" is roughly 6.3 mm. Most Vietnamese green coffee falls between screen 12 and 19, with larger, more uniform beans (16+) commanding a premium because they roast more evenly.
When you see a spec sheet listing "Screen 18, min 90% retention," that means at least 90% of the sample beans are held back by an 18-screen sieve — a shorthand for bean uniformity, not quality on its own.
Defect Counting: The Real Quality Signal
Every 300-gram sample is checked for defects, and each defect type carries a point value — for example, a fully black or fermented bean scores 1.0, a half-black bean scores 0.5, and an immature or shriveled bean scores 0.2. The totals are capped by grade:
- Robusta: Grade 1 typically allows no more than 150 defect points per 300g sample.
- Arabica: Grade 1 typically allows no more than 86 defect points per 300g sample.
- Admixture (foreign variety or foreign matter) is also capped — Grade 2, for instance, allows Robusta content in Arabica lots of no more than roughly 1%.
Moisture must sit at or below 13% for stable storage and shipping, and beans must show natural color and odor with no mustiness, which would signal mold or improper drying.
TCVN Grade vs. SCA Specialty Score — Not the Same Thing
This is where many new buyers get tripped up: a TCVN grade tells you about physical bean quality and defect count, not cup quality. It's entirely possible for a lot to be TCVN Grade 1 and still cup below 80 points on the SCA scale, or conversely for a smaller, high-scoring micro-lot to carry a mixed screen size that wouldn't earn a top TCVN grade on size alone.
For true specialty sourcing, ask for both: the TCVN grade and defect report as your baseline quality control document, and an independent SCA cupping score (80+ for specialty) as proof of flavor quality. Reputable exporters will provide a pre-shipment sample, a cupping report, and a certificate of analysis before you commit to a container.
A Buyer's Checklist
- Screen size and minimum retention percentage
- Defect count per 300g, broken down by defect type
- Moisture percentage (aim for ≤13%)
- Independent SCA cupping score, ideally from a licensed Q-grader
- Admixture/foreign matter percentage
- Pre-shipment sample approval, matched against a retained reference sample
Sourcing With Confidence
At Vietnam Specialty Coffee, every lot we offer to international roasters and importers ships with a full TCVN grading report alongside independent cupping scores, so you're never choosing between paperwork and flavor. If you're building a spec sheet for your next container of Vietnamese Robusta or Arabica, reach out and we'll walk through grade, screen size, and cupping data lot by lot before you commit.