1. Either cold water or hot water can be used for soaking Undaria pinnatifida, but the soaking time in hot water is shorter and the effect is the same. It can be soaked in cold water for about 5 minutes and hot water for about 3 seconds.

2. It should be noted that the foaming rate of dried Undaria pinnatifida is very high. Generally, one kilogram of Undaria pinnatifida can soak 15 kilograms, so don't put too much at a time when foaming Undaria pinnatifida.

3. Undaria pinnatifida will contain seashells in the ocean, and fine sand particles will not be completely removed during sun drying. Before eating, Undaria pinnatifida must be soaked in warm water to make it completely soft, and the sand impurities in the soaked Undaria pinnatifida will settle to the bottom, so it will be cleaned.

4. Dried Undaria pinnatifida can be used to make soup. Boil the dried Undaria pinnatifida with water, and put the soaked Undaria pinnatifida into the prepared soup and stir well.