Seaweed is a low-sodium salt substitute for cooking and table use. It shouldn't be used in baking because it doesn't contain the chemicals needed to react with leavening ingredients that aid in the rising required in the preparation of many baked goods. Although seaweed is much lower in sodium than salt, it does contain some because it is grown in salt water.
Dried seaweed as a salt substitute has a slight nutty flavour in addition to its salty essence. Seaweed is mild and gives foods a fresh flavour. Because it's lower in sodium and not iodised, the flavour is not as intense as pure salt and doesn't have the bitter flavours of iodised table salt when used in excess.
Seaweed is high in calcium, magnesium, potassium, chlorine, sulphur and phosphorus. Its micronutrients include iodine, iron, zinc, copper, selenium, molybdenum, fluoride, manganese, boron, nickel and cobalt. Sea plants, such as the seaweed used as a salt substitute, have organic compounds called phytonutrients that are healthy -- and missing from land plants. Because seaweed is dried for use as a salt substitute, these minerals are concentrated, making it even healthier than eating fresh seaweed as a vegetable.
Types of Seaweed
Kelp, bladderwrack and dulse are types of seaweed used as salt substitutes. A combination is often used when seaweed is labelled and marketed as a salt substitute. These specific seaweeds have the best overall mild seaweed flavour when used as salt substitute, and can also be used as a vegetable if they aren't dried and flaked. They're typically eaten as a vegetable with dressings and vinegars in seaweed salad.
Seaweed must be dried and flaked to be used as a condiment salt substitute. When seaweed is dried it loses about 90 per cent of its total weight from the moisture that evaporates in the drying process. The remaining dry seaweed is then crushed into flakes to be used in cooking or to sprinkle on top of food.