Frozen Atlantic Herring: Whole Round, Fillets and Butterfly Cuts

Product overview

Herring is a raw material first and a dish second. Most frozen herring goes on to be smoked, marinated, salted or fried, and a processor’s recipe works only if the fish arrives at the right size, fat level and freshness. A summer-caught herring heavy with fat makes a rich kipper or matjes-style fillet, while leaner fish caught after spawning give a firmer, less oily flesh that some fryers and canners prefer. We therefore treat catch season and fat as part of the herring specification, alongside size and format, rather than as details discovered after thawing.

Atlantic herring (Clupea harengus) is a schooling clupeid fished by pelagic trawl and purse seine across the North Atlantic. Most of our offers draw on Norwegian spring-spawning herring, North Sea herring and Icelandic summer-spawning herring, landed in Norway, Iceland, the Faroe Islands, the UK and EU states, with North-West Atlantic supply from Canada on request. Baltic herring, a small subspecies, and Pacific herring (Clupea pallasii), a separate species, are never passed off as Atlantic herring; if either suits your use, it is offered under its own name. Herring is not caught in Thai waters, so every lot comes from partner packers, with catch area, vessel and plant declared.

Whole round herring is frozen in blocks soon after landing and graded by fish weight, for example 100⁠–⁠150 g, 150⁠–⁠200 g and 200⁠–⁠300 g, or by fish per kilogram. Filleting plants produce skin-on and skinless single fillets and butterfly fillets, in which the two sides stay joined along the back once the head, guts and backbone are out, frozen in interleaved layers or IQF. Machine filleting removes the backbone and most rib bones but leaves fine intermuscular bones, which curing and marinating soften; if a lower bone level is needed, the tolerance goes into the specification. Packers measure fat by instrument or laboratory analysis, the result can be reported for each lot on request, and roe or milt stage can be noted for buyers who grade on it.

On inspection, buyers look first at the belly: herring caught while feeding heavily can suffer belly burst as digestive enzymes attack the cavity wall, so feed content and freezing speed are worth checking. Rancidity is the other recurring defect, since oxidizing fat turns herring flesh yellow and bitter in long or warm storage. Histamine testing can be arranged per lot, because EU and US food safety rules treat clupeids as a histamine-forming group. Typical buyers are smokehouses, marinade and canning plants in Europe, traders supplying West and North Africa with whole round fish for smoking and frying, and importers serving Eastern European communities. For other oily pelagic fish, see frozen mackerel, and for loading and temperature records, our reefer shipping guide.