Spice Grading Terms Glossary

• Moisture — the percentage of water content in the product; higher moisture increases spoilage risk and reduces effective shelf life.
• Volatile oil — the aromatic oil content responsible for a spice's characteristic smell and flavour intensity; a key quality indicator for spices like coriander and turmeric.
• Foreign matter / extraneous matter — non-product material (stems, stones, dust, other plant matter) present in the lot; lower is better, and this is typically capped at a small percentage.
• Ash content — the residue remaining after a sample is incinerated in testing; used as an indirect indicator of purity and mineral content, and elevated ash can suggest contamination or adulteration.
• Purity — the percentage of the product that is the actual intended item, as opposed to admixture from other varieties, grades, or foreign matter.

• Curcumin content — the active compound in turmeric responsible for colour and much of its market value; expressed as a percentage.
• Piperine content — the compound responsible for black pepper's pungency; expressed as a percentage.
• Scoville Heat Units (SHU) — the standard scale for measuring chilli pungency (heat); higher SHU means hotter.
• ASTA colour value — a standardized scale (from the American Spice Trade Association) used to measure the colour intensity of ground spices, particularly chilli and paprika.
• Bulk density — weight per unit volume (commonly grams per litre), used especially for pepper as an indicator of berry maturity and fill.

• Aflatoxin — a toxin produced by certain moulds that can occur in spices (particularly chilli) under poor storage conditions; regulated with maximum limits in most destination markets.
• Codex limits — reference maximum levels for contaminants set by the Codex Alimentarius, an international food standards body; often used as a general benchmark alongside destination-country-specific limits.
• Certificate of Analysis (CoA) — a lab report confirming a specific lot's tested values against the stated specification.

If a supplier's spec sheet uses a term not covered here, ask them to define it in plain language and, where possible, express it as a testable number — a specification you can't verify against an actual lab result isn't a specification you can rely on.