Frozen vegetables are graded on four axes at once: size or calibre, defect count, colour and uniformity, and the proportion of extraneous vegetable matter. There is no universal A, B, C scale in EU trade. Grade names are commercial labels whose meaning comes from the numbers written next to them in the specification, so “Grade A” without a defect table means nothing enforceable.
Calibre is the primary sorting axis and is usually declared as a band with a minimum percentage in band, for example florets 20 to 40 mm with at least 90 per cent in band. The measurement rule matters as much as the band: the largest dimension, the cut face, or a screen aperture all give different answers on the same lot.
Defects are counted against a defined list on a defined sample mass. Typical categories are mechanical damage, discoloured or bruised pieces, over-mature or fibrous pieces, loose or broken material, and units outside the calibre band. Each carries its own maximum, usually expressed as a percentage by weight on a 500 gram or 1 kilogram sample.
Extraneous vegetable matter is plant material of the same crop that is not the specified part, such as leaf and stalk fragments in a floret product. It is counted separately from foreign material of non-plant origin, which normally has a zero tolerance.
Colour and uniformity are assessed against a retained reference sample or a photographic standard, usually on both frozen and cooked product, because blanch level and variety show up after cooking rather than in the bag.
The Codex Standard for Quick Frozen Vegetables provides an internationally recognised structure for these categories, and it is a reasonable reference framework when a buyer and supplier need neutral vocabulary. It does not replace a bilateral specification.
Grade tiers in practice map to end use: tight calibre and low defect counts for retail packs where the consumer sees the product, wider bands for food service, and the widest for further processing where the product is cut, blended or cooked into a recipe. Paying retail grade for a soup line is a common and avoidable cost.