Wild irish sea veg wild irish sugar kelp 50g sugar kelp has similar qualities to normal kombu while the white powdery substance on dried kombu laminaria ochroleuca is predominantly made up of sodium based minerals the coating on sugar kobmu has a greater quantity of the sugary substance mannitol which lends its distinctive sweetness sugar kelp is found in the extreme lower shore and in gullies and rock pools it has a small holdfast and very short thin stipe which is less than 60cm long