Organic seaweed powder from Dragon Superfoods, made from Ascophyllum nodosum — a brown alga harvested from cold rocky shores in the North Atlantic.
Please read the iodine note before anything else. It genuinely matters. Brown seaweeds concentrate iodine from seawater to an extraordinary degree — hundreds of times the levels in any land plant, and the content varies enormously between harvests and between species. An adult's daily requirement is about 150 micrograms, and the European Food Safety Authority sets a tolerable upper limit of 600 micrograms a day. A single gram of some brown seaweed powders can exceed that upper limit several times over.
Excess iodine is not harmless. It can cause both hyperthyroidism and hypothyroidism, and it is a particular risk for anyone with existing thyroid disease, anyone on thyroid medication, and during pregnancy and breastfeeding, where excess iodine can affect the baby's thyroid. Use the dose stated on the packet and no more, do not use it daily over long periods without medical advice, and if you have any thyroid condition, speak to your doctor before using seaweed at all. This is one of the very few foods in the shop where the quantity genuinely matters.
A naming correction. Ascophyllum nodosum is knotted wrack, and it is not strictly a kelp — true kelps belong to the order Laminariales, and Ascophyllum belongs to the Fucales. The word “kelp” is used loosely for almost any large brown seaweed in the supplement trade. Worth knowing, because iodine content differs substantially between species and a label saying “kelp” does not tell you which one you have.
What it tastes like and how to use it. Strongly marine, savoury and salty — glutamate-rich, which is why seaweed is a natural umami ingredient. A very small pinch deepens a stock, a miso soup, a tomato sauce or a bean dish, and it can partly replace salt. Use it as a seasoning rather than a supplement, which is both the safer approach and the better-tasting one.
Available at Só Verde, an organic concept store in Foz, Porto.