Glaze has a real job. It is not padding, and a product with no glaze at all is usually a product that will dehydrate in storage. The problem is not that glaze exists; it is that it is often left unstated.
What glaze does
A thin layer of ice on the surface of frozen seafood acts as a barrier against two forms of damage:
- Dehydration — freezer burn, where moisture sublimates out of the surface of the product.
- Oxidation — rancidity in fatty species, where surface fat reacts with oxygen.
Fatty pelagic species and delicate shellfish benefit most. A glaze layer that is too thin fails to protect; one that is too thick is being sold as product.
Reasonable percentages
There is no single correct figure. The right glaze depends on the species, the surface area of the piece, the expected storage duration and the transport route. What matters commercially is that the figure is declared, bounded and verified, not that it hits a particular number.
Our own salted and smoked cod loin articles, for example, are produced at a declared 5 % glaze. Because the figure is declared, the net weight underneath it is a known quantity rather than something to discover on arrival.
The four clauses
A glaze agreement that holds up has four parts.
1. The percentage. Stated as a number with a tolerance, for example “5 %, maximum 7 %”. A range with no ceiling is not a specification.
2. The weight basis. Explicitly: price is per kilogram net of glaze. See net weight and gross weight.
3. The verification method. How glaze will be removed for measurement, what sample size, and who performs it. Without this, the percentage is unenforceable.
4. The remedy. What happens if the measured figure exceeds the agreed maximum. Usually a weight adjustment against the invoice; occasionally rejection.
Common failure modes
- Glaze stated in the offer, absent from the purchase order. The offer is not the contract.
- A grade band measured post-glaze. A 5–8 oz cluster grade measured after glazing is a smaller cluster than the same grade measured before. State which.
- “Lightly glazed.” This is not a percentage.
- Glaze percentage agreed verbally. If it is not on the specification sheet and the invoice, it will not survive a dispute.
A note on re-glazing
Product that has been thawed and refrozen may be re-glazed in the process. If freezing history matters to you — and it should — ask for it explicitly rather than inferring it from the glaze. See single frozen and double frozen.