Smoked Haddock Sandwich

A cold-smoked haddock fillet has gone through woodsmoke for hours and is still, in the strict sense, raw fish, which is the first thing this sandwich has to deal with. The smoke flavours and lightly cures the flesh but never cooks it, so unlike a slice of cold-smoked salmon the fillet cannot simply be laid on bread. It is poached, gently, in milk or barely trembling water until it turns from translucent to opaque and lifts off the skin in clean white sheets. What goes between the bread is therefore cooked from a cured starting point, warm then cooled, a mild and savoury flake carrying a thread of smoke rather than a ready-to-eat slice.

The poach is the whole game, and it is over in a few minutes. Lift the fillet too late and the flesh tightens to something dry and ropey, the soft leaved texture gone. Lift it too early and the centre stays glassy and raw. Hold the milk at a real boil and the outside shreds before the middle sets. Get the timing right and the haddock comes off the skin in broad warm flakes that you break, never mash, into pieces the bread can hold.

Everything around the fish is chosen to keep out of its way. The flake is bound with only enough butter or mayonnaise to make it cohere, since over-mixing turns a delicate fish to wet paste and wastes the careful poach. The bread is soft and plain and buttered to both faces, the fat sealing the crumb so a faintly moist filling does not soak it through; a hard crust would simply bully a flake this fragile. The smoke is gentle, so the seasoning is sharp and small against it: a squeeze of lemon, a heavy grind of black pepper, often a few sprigs of watercress laid in for a peppery green snap against an otherwise all-soft bite.

Open one and the smell comes up first, woodsmoke over clean cooked fish and the warm dairy note of the poaching milk still on the flake. The haddock is pale straw rather than orange, soft and faintly glistening, and it yields the instant you bite with no resistance at all. The smoke lands, then the mild sweet fish, then the salt of the cure, with the lemon cutting a bright line through it and the pepper catching at the back. Where a poached or soft egg has been laid over the warm flake, the yolk breaks into the crumb and the bite goes richer and looser, the bread underneath darkening a little where fish oil and yolk have met.

The colour is the argument worth knowing, because two fillets that look like different fish are the same fish handled two ways. Smoked over real wood, haddock comes out a pale straw or honey colour and no brighter. The vivid canary-yellow fillet on most supermarket shelves has been dyed, usually with annatto or a touch of curcumin, a purely cosmetic stain that in the days before refrigeration read as a sign of freshness and quality. A good deal of dyed haddock is also coloured to stand in for smoke it barely got, run through machinery rather than hung over a fire. The undyed fillet is the one that tastes of what it claims, and it is what a careful smoked haddock sandwich is built on.

The variations turn on the binder and the company the fish keeps. A version held with crème fraîche in place of mayonnaise reads lighter and lets the smoke come through more cleanly. Chopped hard egg worked through the flake pushes it toward a breakfast register without the rice and spice that would make it another dish entirely. Watercress, rocket, or a slick of grain mustard each change the counter without touching the fish. The dyed fillet makes a brasher, more strongly cured sandwich at the cost of the subtlety the pale version trades on, and the battered fried haddock between bread is a separate sandwich that shares only the name of the fish.

From Findon to a Protected Name

The pale smoked haddock has a heartland and a named ancestor. The Finnan haddie is a cold-smoked haddock from Findon, a fishing village just south of Aberdeen, where fishwives once hung lightly salted fish in their chimneys to take the smoke of peat and green wood; haddie is simply the Scots word for haddock. The origin is not quite settled, and an older tradition gives the credit to Findhorn in Moray instead, but the Findon line is the one the name carries. Admired in Scotland for generations, the cured fish reached London only in the 1830s and spread once the railway linked Aberdeen to the capital in the 1840s and the short-keeping fish could travel.

The same cold smoke became a trade on the English coast at Grimsby, where smokehouses have cured cod and haddock since the 1850s by hanging the fillets overnight in tall brick chimneys above smouldering sawdust, with no heat added so the fish takes smoke without cooking. When motorised kilns arrived in the 1940s and turned out coloured fish in a fraction of the time, the slow houses leaned on the difference between fish that is smoked and fish that is merely cured to look it.

That distinction is now written into law. The pale, properly smoked fillet a sandwich wants is the one coloured by a chimney fire over sawdust rather than by a stain, and in October 2009 the European Commission gave it a name to stand on, granting Traditional Grimsby Smoked Fish a Protected Geographical Indication that reserves the title for cod and haddock cold-smoked the old way within a defined stretch of coast around the Lincolnshire port.