1, add vinegar.

Because kelp contains gum such as fucoidan, which is insoluble in water, it expands rapidly after absorbing water and becomes a sticky colloid on the surface of kelp, preventing water from entering further, so it is usually difficult to soak dried kelp thoroughly. If you add some vinegar when soaking kelp, the acidity of vinegar will easily destroy these gums that prevent water from entering, and kelp will soon soften.

It is not advisable to use hot water. In addition, don't use hot water to soak dried kelp, because hot water will make kelp lose a lot of nutrients, so you can use cold water or warm water.

3. Steam first and then soak. The research results of nutrition experts show that the nutritional loss of dried kelp is the least after cooking and soaking. That is, put dried kelp in a steamer for 30 minutes, take it out, rub it with alkaline flour, and soak it in clean water for 2-3 hours. Soak the kelp with your hands, and you can easily pinch it off. It is not advisable to soak for too long, otherwise the nutrients will dissolve into the water.