There are three main groups of seaweed; green, red and brown.
The higher or closest to the shore, in shallower waters are usually green, as they get a fair amount of light passing over them and photosynthesis is possible, the deeper we go and the colours change to reds and browns as less light has penetrated the water, that’s the theory, but as with all things wild there are no set patterns and all can often be found together.
The green ones are usually more delicate in texture and the brown ones the “toughest”. Harvesting one of each would make for a balanced and comprehensive range of vitamins, minerals, carbs and protein.
There are no poisonous seaweeds, although not all are edible, and some grow at extreme depths that are so alkaline in there makeup, that consuming them would be detrimental to your digestive system.
We must first look at seaweed as we would any vegetable, young vibrant growths for example, still firmly attached to the rock.
A void any seaweed washed up on the beach or floating around loose, firstly if it’s not attached to the rocks it may be dead/composting containing harmful bacteria growth, or it may be one of the deep water alkaline varieties. The only exception would be just after or during a new storm when fresh plants are torn from there hold fasts and dumped on the beach, you will also need to be confident in your identification of particular seaweeds to eliminate any undesirables.
Many of the seaweeds you can easily find at low tide, will be high and dry, possibly covered in grit, sand or muddy deposits, wash your harvested seaweed in clear sea water, an isolated rock pool is ideal, plunge the seaweed up and down, separating it and allowing the grit etc to fall through the water, the seaweed will float back to the surface.
Avoid cleaning the seaweed (or any other seafood) for that matter), in fresh water, as the density difference between that of salt and fresh water is different, fresh water will leach out a lot of goodness and enter the tissue structure.
Once you have harvested your seaweed, and after eating the initial meal, you can start to dry any spare above the fire or on warm dry rocks in the sun.
How long you cook each individual seaweed will depend on its unique structure, if when chewing the cooked seaweed it doesn’t easily break down after a few chews, it would’ve been sensible to cook it for longer, as the energy the body will draw on to digest the vegetable matter may out way the calorific benefits, this can be true of most foods.
Store your dried seaweed in an airtight as possible container or wrap. After drying or toasting it may be possible to crush and even powder the seaweed to reduce its apparent volume.
(this is an extract written by Fraser Christian for the next handbook)