…possessed in tack by Mrs Anne Campbell ; transmitted, with Specimens of Kelp made in 1821, by Alexander Macleod, her Factor.
1st, The quantity of kelp manufactured on the farm of Strond, this season, was 115 tons.
2d, All the kelp was made from cut-ware of two years growth.
3d, The plants used were Fucus nodosus, or ladyware ; Fucus vesiculosus, or bell-ware; and Fucus serratus, or black-ware.
He goes into detail about these three species and then describes the manufacturing process:
1 The ware is cut off the rocks with a common hook, similar to that used for shearing (reaping,) but stronger, and having a rougher edge.
2 Care is taken to land the ware on clean spreading ground; and if any sand or mud is found to stick to the ware, it is always washed before landing it.
3 The ware is spread out every dry day, and made into small cocks at night. When, in this way, it is found to be pretty dry, it is made into larger cocks, and left to heat in them for six or eight days; but if the ware is of that description which I have mentioned above, as growing in bays, into which there is a run of water, such ware is always left in large cocks from fifteen to twenty days.
4 The ware being thus secured, a dry day, with a good breeze of wind, is watched for, in order to burn it.
5 The kelp-kilns are constructed of middle sized stones, of hard texture, and built up carelessly ; the outsides of the kilns are covered with turf: the length of each kiln is from 15 to 18 feet; breadth 2½ feet, height 2 feet. They are made on the surface of the ground, and on the firmest sward they can find.
6 The process of burning is as follows: A small bundle of straw or heather is set on fire; the dryest part of the ware is placed over this, and gradually added, until the flames become general through the kiln; then the ware to be burnt is thrown in, little by little, till the whole is reduced to ashes. If, however, it happens, that the day is too calm, or that the ware is not sufficiently dry, so that the ashes cool, and cake into white crusts, the manufacturer stops burning any more, until he rakes all the ashes in the kiln; then commences burning again, and goes on in this way until he has the whole thoroughly burnt. Want of attention to this method leaves kelp of a white colour, and porous texture.
7 The last process is the raking or working of the ashes with an iron with a wooden handle, made for the purpose, until the whole is brought into a solid semi-vitrified state. Most manufacturers commence this process immediately after the last part of the ware is put on the kiln, and when a good deal of the ware is not sufficiently burnt, and of a black colour. The Strond manufacturers, however, do not commence raking the ashes for at least half an hour after the last of the ware is put on; so that the whole may be thoroughly burnt. Want of attention to this particular leaves kelp of an ugly black colour. The raking of the ashes is simply done, by working the kelp-irons through it, until the whole becomes a semi-vitrified mass: three or four men are employed at this process. If fewer, the ashes will not be sufficiently worked, and consequently a great part of them must be mixed in the next burning.
Finally, The kelp is broken into pieces of about 2 cwt.: these are made into conical heaps, covered with dry ware, and over that is placed a layer of turf, which secures the kelp tolerably well, if early shipped.
This is the fullest contemporary account that I have found of the processes involved in Kelp-making and I think Alexander Macleod, the Factor, has been extremely thorough. As the industry was in decline at this time, we can be sure that he was doing his very best to promote the excellent quality of the Kelp from the Farm of Strond in Harris!
The full account, including those from three other areas of Kelp Manufacturing, can be read here:
Transactions of the Highland and Agricultural Society of Scotland
Royal Highland and Agricultural Society of Scotland 1824
p251-257 on Improving the Manufacture of Kelp
A modern company harvesting sea-ware – http://www.hebrideanseaweed.co.uk/history.html