Using Seaweed in British Home Cooking

Why seaweed suits British cooking

We live on an island wrapped in edible seaweed, yet most of it still goes into the compost or gets kicked about on the beach. That is a shame, because seaweed is one of the most useful things you can keep in a British kitchen cupboard. It brings glutamates — the same savoury depth you get from anchovies, Parmesan or long-simmered stock — and it does it without shouting. Used with a light hand, nobody will say "this tastes of the sea". They will just say it tastes good.

The mistake most people make is treating seaweed as a vegetable to be piled on the plate. Treat it instead as a seasoning, in the same family as a bay leaf or a splash of Worcestershire sauce. A teaspoon of the right powder can lift a pot of lentil soup, a loaf of soda bread or a dish of new potatoes further than almost anything else in the cupboard.

Choosing and buying the right seaweed

Different seaweeds do different jobs, and it helps to know what you are reaching for.

• Kombu or sugar kelp — thick, wide blades. The workhorse for stocks and broths, and the best seaweed to grind into a general-purpose seasoning powder.
• Dulse — soft, reddish fronds with a slightly smoky, bacon-ish note. Wonderful fried in butter until crisp, or flaked into scones and cheese straws.
• Laver — the Welsh classic, sold as laverbread. Nutty and dense, excellent with oats and bacon, or stirred through a bread dough.
• Pepper dulse — small, dark and surprisingly truffly. Use it raw, scattered over hot buttered toast or a bowl of shellfish.
• Wakame and sea spaghetti — rehydrate well and add texture to salads and pickles.

Dried seaweed is the practical choice for most of us. Buy from a small British or Irish producer where you can, and look for sheets or flakes that are crisp, springy and smell sweetly of the shore. Anything brown, dusty or musty has been sitting about too long. If you do forage, cut rather than pull, leave the holdfast attached to the rock so it can regrow, avoid anything near harbour walls, outfalls or busy road runoff, and check local byelaws before you take anything home.

Drying, toasting and grinding at home

Fresh seaweed keeps only a day or two in the fridge, so dry anything you are not using straight away. Rinse it briefly in cold water, spread it out on a rack and either leave it in a warm airing cupboard for a few days or dry it in an oven at about 50°C with the door slightly ajar for two to three hours. It is ready when it snaps cleanly rather than bending.

Toasting transforms it. Hold a sheet over a gas flame or lay it in a dry frying pan for twenty or thirty seconds a side, until it darkens and smells nutty. Then grind it in a spice grinder with a pinch of coarse salt — the salt stops the powder clumping — and sieve out any tough stems. Keep it in a small airtight jar in the dark, with a few grains of rice to catch moisture. It will hold its punch for about a year; if it turns soft, refresh it in a low oven.

Simmering: stocks, soups and stews

This is where seaweed earns its keep. Put a 10cm square of dried kelp, roughly 5g, into a litre of cold water and bring it up to just below a simmer. Hold it there for fifteen to twenty minutes, then lift the kelp out before it turns slimy or bitter. Use that liquor as the base of a soup, a risotto, a casserole or a pot of braised beans.

You can also simply drop a piece in with whatever is already cooking. A square of kelp with boiling potatoes, a spoonful of dulse flakes in a fish pie sauce, a strip of kombu tucked into a chicken casserole: all add a quiet bass note underneath the other flavours. Do not boil seaweed hard for a long time, and do not leave it in overnight unless the recipe is designed for it.

Bread, scones and other bakes

One to two teaspoons of ground seaweed per 500g of flour is plenty in a loaf. Wholemeal and rye doughs take it particularly well, as do soda breads, where the seaweed's savoury edge sits nicely against buttermilk. For a bit of texture, soak a tablespoon of dulse flakes in warm water for five minutes, drain well and fold them through the dough at the end of kneading.

Laverbread is the classic here — two generous tablespoons stirred into a white or wholemeal dough gives a dark, faintly green crumb with a deep, almost mushroomy flavour. Cheese scones with a teaspoon of ground kelp and a handful of flaked dulse are another easy win, as are cheese straws dusted with seaweed salt before they go in the oven.

Butters, salts and finishing touches

Seaweed butter is the fastest way to convert a sceptic. Beat 100g of soft butter with a teaspoon of ground kelp or two teaspoons of crushed, toasted dulse, the zest of half a lemon and a good pinch of salt. Roll it in cling film, chill it, and melt slices over new potatoes, grilled fish, roast carrots or a plain jacket potato.

A seaweed salt is just as useful: blitz four parts flaky sea salt with one part seaweed powder and keep it in a small dish by the hob. Finish chips, fried eggs, roast chicken or a bowl of greens with it. And keep a bag of dulse in the cupboard for those evenings when you want something salty and crisp with a drink — thirty seconds a side in a dry pan, and it shatters like a prawn cracker.