How do I cook smoked haddock and kippers without it being too salty?

Smoked fish in Britain is cured with salt before it is smoked, and cure strength varies enormously between producers. The same recipe can produce a perfect dish from one fishmonger and something inedible from another, which is why every traditional method for smoked haddock involves milk — it is a salt-extraction step disguised as a cooking method.

What you'll need

• Smoked haddock, kippers or smoked mackerel
• Milk, or milk and water
• A wide shallow pan with a lid
• Bay leaf, peppercorns (optional)

Step by step

1. Choose undyed if you have the choice.The bright yellow-orange colour on most smoked haddock is dye — traditionally annatto, now often a permitted food colour — applied because pale smoked fish sold badly. Undyed smoked haddock is the same fish, straw coloured, and usually properly smoked rather than lightly smoked and coloured.
2. Taste the cure before you commit.Cut off a corner and cook it for thirty seconds in a little water. If it is punishingly salty, soak the fillet; if it is mild, go straight to poaching. Thirty seconds of checking saves a whole dish.
3. Soak a very salty fillet before cooking.Twenty to thirty minutes in cold milk or cold water in the fridge, then discard that liquid and poach in fresh. Longer than that and you start losing the smoke flavour you paid for.
4. Poach in milk at a bare simmer, never a boil.Lay the fillets in a wide pan, pour over just enough milk to cover, add a bay leaf and a few peppercorns, and bring it barely to a tremble. Six to eight minutes for a standard fillet. Boiling toughens the fish and makes the milk catch.
5. Take the fish out and keep the milk.That milk is now smoked fish stock. It becomes the sauce for the fish pie, the liquid for the kedgeree rice, or the base of a chowder. Strain it. Throwing it away is throwing away the flavour.
6. For kippers, use the jug method.Stand the kipper tail-up in a tall jug, pour boiling water over it to cover, and leave for five minutes. It cooks through, comes out hot and clean, and the smell stays in the jug instead of in the kitchen for two days.
7. For smoked mackerel, do nothing at all.Hot-smoked mackerel is already cooked. Warm it briefly if you want, but it is designed to be eaten as it is — flaked into salads, mashed into pâté with crème fraîche, lemon and horseradish, or stirred through pasta at the end.
8. Season the finished dish last, and taste first.Anything containing smoked fish rarely needs added salt. Season the sauce, the rice or the mash only after the fish has gone in and you have tasted it.

Tips

• Smoked haddock and a poached egg on top is the whole point of the fish — the yolk does the job a sauce would.
• Grilling smoked haddock with butter and pepper works well and is faster than poaching, but there is no milk to extract salt, so only do it with a mild cure.
• Arbroath smokies and Finnan haddock are traditional Scottish cures and are worth trying — smokies are hot-smoked and ready to eat, Finnan is cold-smoked and needs cooking.
• If you are making kedgeree, poach the fish in the milk first and then cook the rice in a mix of that milk and stock. It is the single biggest improvement to the dish.
• Smoked cod and smoked pollack are cheaper than smoked haddock and behave identically.

Common mistakes

• Boiling smoked fish — It tightens the protein into rubbery strands and pushes salt into the flesh rather than out of it. A bare tremble is the whole technique, and it takes the same amount of time.
• Salting the dish before the smoked fish goes in — Smoked fish carries a lot of salt and releases it into whatever it is cooked with. Season at the very end, after tasting, or you end up with something no one can eat.
• Throwing away the poaching milk — It is the best-flavoured liquid in the kitchen at that moment. It makes the sauce, the soup base or the rice liquid, and buying fish stock to replace it is absurd.

If it doesn't work

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