It usually takes three hours to soak.

There are two types of kelp knots. One is dry kelp knots. This kind of kelp knot itself is dry and needs to be soaked and softened before it can be eaten. Moreover, the dry kelp knots have more salt. Therefore, such dried kelp knots need to be soaked for 3 hours until the kelp knots are soft and bland before they can be eaten. The tidal kelp knot itself is already soft and contains less salt, so you can buy it and soak it for about an hour at home, mainly to remove the sediment inside.

Kelp is rich in carbohydrates and low in protein and fat. Compared with spinach and rapeseed, kelp contains vitamin C, and its crude protein, sugar, calcium, and iron contents are several to dozens of times higher. Kelp is a type of seaweed that is high in iodine. Cultured kelp generally contains 3% to 5% iodine, and as much as 7% to 10%.