Sargassum, the seaweed of the sea
Hai Zao simply means “the seaweed of the sea”. It is not a plant: it is two brown seaweeds, sargassums, attached to rocks in shallow, wave-beaten coastal waters. The Chinese pharmacopoeia accepts large-blade sargassum and small-blade sargassum, Sargassum fusiforme, smaller and fleshier, with spindle-shaped floats. They are harvested in summer and autumn, by hand or with a scythe; Shandong and Fujian are the two main producing regions. Before use, the seaweed is briefly soaked in fresh water to remove salt and sand, then cut and sun-dried. A good harvest is blackish-brown, and becomes supple and slippery again once moistened.
The salty flavour that softens
In Traditional Chinese Medicine, sargassum is cold, bitter and salty. Salty softens, bitter dries and makes things descend, cold clears; of the three, it is the salty flavour that matters most, as tradition gives it the property of softening what has hardened. Associated with the Liver, which governs the free flow of Qi, the Stomach and the Kidney, it is one of the reference substances for dispersing what has knotted and dissolving Phlegm, in the broad sense tradition gives this word: whatever thickens and sets into a mass. The classical texts already credited it with breaking up and dispersing knotted Qi.
Sargassum and kelp, a pair of seaweeds
Its action on water, carried by the downward movement of the salty flavour, is secondary; the ancient texts nonetheless note that it opens the flow of urine. Sargassum is almost always used with kelp, the classic pair of seaweeds in the Chinese pharmacopoeia. Both are salty and cold; sargassum enters the Liver more clearly and is considered the best for what has clumped together, while kelp is a little stronger on water. They can be told apart at a glance: kelp is a flat, ribbon-like blade, sargassum a branching bush with visible floats.
Key benefits
Excess dispelled & knots softened
Through its salty flavour, sargassum softens what has hardened and helps dispel internal excess, according to Chinese tradition.
Qi unknotted & free flow
Associated with the Liver, it disperses knotted Qi and supports its free flow.
Urinary comfort & water in motion
Salty makes things descend: it lets water flow and promotes urinary comfort.
