‘We check the eyes, the gills, the firmness of the meat’: the art of smoking fish in Grimsby

When the wind is right, the Cook & Lucas smokehouse lights the fires that smoke the fish that go into Charlie Bigham’s pies. Photograph: Emli Bendixen/The Guardian

Grimsby’s fish dock is dotted with faded signs on weathered brickwork, and the distinctive, pointed chimneys that tell visitors they’ve reached the home of traditional Grimsby smoked fish. Like Melton Mowbray pork pies and Dundee cake, this celebrated product has been afforded protected geographical indication status – which means only cod and haddock that’s been traditionally cold-smoked in this particular corner of north-east Lincolnshire can claim the name.

Among the seven producers of this smoked fish is Cook & Lucas, which supplies haddock to Charlie Bigham’s, the oven-ready food company, which uses it in its best-selling fish pies.