Kelp powder substitutes

This is not really a substitution, it is the same ingredient in a cheaper form, and kombu is stocked far more widely than jarred kelp powder. Break the sheet into pieces, blitz it in a spice grinder until fine and sift out any tough fragments. The taste is identical: gently sweet, mineral and deeply savoury. Freshly ground it is actually more aromatic than a jar that has been open for months.

Best for

broths and dashi, low-sodium seasoning, rice and grains, vegan fish-style dishes, salad dressings

Wipe kombu with a dry cloth rather than rinsing it. That white bloom on the surface is flavour, not dirt or mould, and washing it away costs you savouriness.

A genuinely good swap and often easier to find, sold on its own or in dulse and kelp seasoning blends. Dulse is a red seaweed and it tastes noticeably different: saltier, smokier and with an almost bacon-like savouriness, and it tints food reddish-brown rather than green-grey. That makes it better than kelp on popcorn, eggs and avocado toast, and less right in a delicate clear broth where its smokiness stands out.

Best for

popcorn and snacks, eggs, salads and dressings, vegan bacon-style flavour, soups

Dulse is saltier than kelp powder, so taste before adding the recipe's salt. Flakes stay visible; blitz them if you want a smooth result.

Nori, the sushi sheet, toasts and grinds easily and tastes toasty and faintly tea-like, with less savoury power than kelp and a cleaner, less mineral finish. It is the best option for sprinkling on rice, eggs and popcorn. Wakame is silkier and slightly sweeter but is usually sold to be rehydrated rather than ground, so the powder is less common. Both add green-black flecks, which is very visible on pale food.

Best for

rice and onigiri, eggs, popcorn, noodle bowls, finishing sprinkle

Toast a nori sheet briefly over a low flame or in a dry pan until it crackles, then crumble and grind. Untoasted nori grinds unevenly and tastes flat.

Convenient and delivers a much bigger savoury hit, because most instant dashi combines kelp with dried bonito plus added salt and MSG. That is also the catch: it is not vegan, it is far saltier, and it tastes distinctly smoky and fishy rather than cleanly oceanic. Ideal if you were using kelp powder for umami in a soup, wrong if you were using it to reduce your sodium, since it does the opposite.

Best for

miso soup, noodle broth, simmered vegetables, quick dashi

Contains fish, so it is unsuitable for vegan cooking and for fish allergies. Remove essentially all of the recipe's salt and taste at the end.

The most efficient answer if your reason for using kelp powder was to season with less salt, because kelp works largely through its natural glutamates and MSG is that compound in pure form. It delivers the savoury lift with about a third of the sodium of table salt and no colour or flecks at all. What it cannot give you is aroma: there is no marine, mineral or seaweed note whatsoever.

Best for

low-sodium cooking, soups and stews, vegetables, meat seasoning

MSG is potent at this dose. Start with an eighth of a teaspoon for a dish serving four and taste before adding more. If you would rather not use MSG, a teaspoon of nutritional yeast gives a milder, nuttier savoury lift with no sodium at all, though it leaves visible yellow flakes.

Worth stating plainly: if kelp powder was in the recipe to make a vegan crab cake, a plant-based tuna salad or a seaweed-flavoured broth actually taste of the ocean, no non-seaweed ingredient will do it. Nutritional yeast, MSG and bouillon all give savouriness without the marine note, and the dish will simply read as savoury rather than as seafood. Buy any seaweed at all, even a packet of sushi nori, rather than faking it.

Best for

vegan seafood dishes, plant-based tuna and crab, seaweed broths

A single sheet of nori from a sushi kit, toasted and crumbled, is enough for several batches and is stocked in most supermarkets.