Wool and sea water

Estonian Native Sheep. Sample 8

Estonian Native Sheep. Sample 8

When working with my Estonian Native Sheep wool samples I got interested in how salt affects wool. I also wanted to know if soaking wool in sea water has been common in Scandinavia and the Baltic countries. I turned to the spinners on Ravelry and Facebook. Spinners from Scandinavia, the Netherlands, UK, and US responded at once!

On Ravelry I wrote: “I got a few samples of Native Estonian Sheep (Eesti maalammas) wool. It’s been scoured in the traditional way in many coastal areas around the Baltic Sea and the Gulf of Finland, by soaking it in the sea. The wool feels quite different from other wools I’ve worked with, dry at first and when I tease and card it I can feel the lanolin. Some of the samples are very fragile, which can be a result of long storing, but I wonder if it can also be a result of the salt in the water. The Baltic Sea and the Gulf of Finland have brackish water. I asked: “Do you know what sea water does to the wool except cleaning it to some extent? What happens to it?” The discussion was held in English.

On Facebook I asked: “Do you know what sea water does to wool, that is, how does salty (brackish) sea water affect wool that is scoured in the sea?” I also asked: “How common has it been to wash wool in the sea or in sea water on our coasts?” By “costs” I meant Scandinavia, as the members in the group in question are primarily from Sweden, Norway and Denmark. The discussion was held in Swedish and Norwegian.

I also had some answers from British members in Online Guild of Weavers, Spinners and Dyers. They tell about sailors in the Royal Navy and the merchant fleet washing their clothes in sea water all over the world in the first half of the 20th century. One person has heard that wool was washed in sea water in Faeroe in the old days. Another tells about a bay called “Sheep Wash” in Wales, where the farmers did just that: washed sheep.

Below is a summary of the discussions on Ravelry and Facebook as by Friday, 18 October 2013 at 5 pm Finnish time. Both communities are closed, so I will not tell who said what. Quotes from Ravelry are surrounded by quotation marks. There are no quotes from Facebook, as that discussion is interpreted in English by me. If I have misunderstood or interpreted in a wrong way, please contact me or comment in this blog’s Comments, and we’ll get it right. I have asked the participants in both discussions for permission to publish this summary. I have checked with Ravelry that it doesn’t violate Ravelry rules. I haven’t found anything on Facebook that forbids it either.

Now then. An attempt to make categories will perhaps make this easier. I did not cut posts that discuss more than one aspect of wool and salt.

I have also added some information, mostly links, that where not included in the original discussions.

1. Customs and traditions

An informant from Norway says that mittens and socks have been washed in sea water, and that sea water is considered to be a gentle detergent. A Norwegian book about housework “Husmorboka” (several editions) says that salt is a cheap and gentle detergent for wool. It says that salt makes the woollies softer.

An informant from Sweden with roots in Estonia says that in the 1930s Estonian sheep were washed in a fresh water stream that had been dammed up.

A Swedish informant says that especially on the west coast of Sweden it was common to wash woollies in sea water or in fresh water with added salt. It was told that women who moved to the inland added salt to the laundry water and that people there laughed at them because they held it to be completely unnecessary.

An informant from the US says: “Many years ago this came up as a question on Fibernet (one of the first if not the very first fibre oriented mailing lists).

Variations of soaking the wool in the sea seem to have been practised in many places in Europe. For instance, in the Netherlands, supposedly sheep were driven through the sea about a week before they were sheared to make the shearing easier. They’d be soaked in seawater but by the time shearing came around, they would have dried off.

A chemist on the list (whose name I can almost but not quite remember) said that the interaction between the lanolin and various forms of salt in the water would produce soap, which would help lift some of the lanolin and dirt away from the fleece.

All soaps, so far as I know, are alkaline. Soaking too long in a soap solution will make wool feel rough at first and then become brittle.

My guess would be that with the wool you are processing, the staple formation protected the cores of the locks from being exposed to the brackish water, ending up with staples that are harsh and/or brittle around the outside with a core of greasy unaffected wool in the centre.”

An informant from the Netherlands says: “In my country the common practise always has been to pre soak a fleece for a day in water with added salt. Preferably rain water – so I was told years ago. This was done to get rid of dirt and sheep’s sweat. Not so much to remove lanoline, allthough some of it came out as well. Rinsing with clean water also was prescribed, for the salt should not stay in the dry wool – it would make wool brittle. I have cleaned my wool that way for many years, but then concluded that I really like to spin my wool without grease at all – and started to wash my raw wool with soap before spinning. (I do pre soak, but in clean water)

I think this discussion is very interesting – thank you!

I have found a restored sheep wash pond in my village. It has been there for a long time, since de middle ages – and almost had gone – luckily it now is restored and bears a sign where the phenomenon is explained to bypassers.”

This informant also linked to a video showing sheep being washed in the 1930s:

A post by Barbro with quotes from an e-mail:  “I have an answer from the sheep farmer (her name is Kadri) in Estonia:

‘In Muhu sheep were washed in sea before shearing. I did it also when I still had only a few animals. Makes shearing much nicer. Nowadays we mostly only soak wool to get rid of the crap and juniper needles and wash it later in luke warm water so we can send most of it to the factory.

Some of it I spin myself for extra warm and water resistant stockings and then I only wash ready made stockings.
My grandma always made grandpas fishermans garment of the wool not too washed.

Actually about sea minerals – back in soviet times Saaremaa wool was known to be more soft than mainland wool because sheep grazed on seashore meadows with more minerals. I’m not sure these minerals work when applied outwardly, but when taken inside they are only a benefit for the wool :)’

She also says that the wool she sent me was winter wool, and thus not of the best quality, because that’s what she had when she got the request for samples. She says the sheep that provided the brittle samples had been badly attacked by horse flies, so the wool was damaged from start.”

A Swedish informant says that wool was probably washed in the water that was at hand.

Barbro told about her grandmother doing her laundry in sea water in periods when there wasn’t enough fresh water. This happened in the 50s in the Ostrobothnian countryside on the coast. They also had to use sea water as drinking water for the livestock, but this could only be done in short periods. The water is brackish. No knowledge of wool being washed in seawater, as my grandmother didn’t spin any longer in the 50s.

2. Sea water and wool

This part of the discussion deals with what happens when wool or clothes come in contact with sea water.

A spinner from the US (California) said: “Very interesting. I am going to have to try this just for fun and learn more about it. I don’t know if I want to use the sea (ocean) water where I am. I don’t like to swim in it because it is so foul. But clean sea water would be nice to try. I will get some next time I go up the coast and try a small batch.”

A spinner from the US (the east coast): “My experience of ocean water is that it’s corrosive. I expect short-term exposure has no effect if the item (whether fleece or sweater–or bathing suit, for that matter:-)) is well rinsed afterward, but I wouldn’t consider soaking anything in seawater.”

A spinner from the US gave advice on saving brittle wool: “Even if there isn’t any salt in the water to start with, sheep sweat a lot and produce plenty of their own salt. That’s the idea behind the fermented suint bath method of prepping fleece.

The brittle fleece is probably too far gone to remedy but for any fleece that feels rough to the touch, giving it a bath in water with a glug of vinegar may help in correcting the pH and removing the remnants of any soap that may still be in the fibre.”

Estonian Native Sheep. Two brittle samples

Estonian Native Sheep. Two brittle samples

A spinner from the US gave a link to a handbook for shipping wool. There’s a paragraph that deals with damages from sea water: Cargo Handbook, Wool.

A Swedish informant says that his family bought 20-25 kilos of yarn from a shop that was to shut down. It was used for felting and some of it was also dyed with mushrooms. The yarn had been at the bottom of the Atlantic Ocean for several years. It was a bit harsh, but very durable.

Another Swedish informant said the Paracas textiles lay buried in the desert sand on the coast of Peru for 2000 years. The sand has high salinity, but it hadn’t effected the textiles. Now air and wrong pH destroy them.

(Link to the Paracas in Gothenburg)

An informant from the US (east coast, same person as above). “I’ve never deliberately washed anything in salt water.” In an earlier post she answered my question about how long the textiles that rotted had been in sea water: “No, not in the water. But if you hang salt-water-soaked clothes to dry as they are (i.e., without rinsing), the results are weakened fabric. Eventually you get easy tearing along any creases. And repeated or lengthy exposure has much the same effect on clothes as it has on car bodies.

Incidentally, I can’t imagine anyone getting out of the water and saying, “Oh, I just love what that swim did for my hair!”:-) I tended to head for a shampoo pretty promptly.

I’ve lived next to the Atlantic Ocean for most of my life, and for the first 30 years spent a fair amount of time immersed in it.:-) Any clothes not washed or well rinsed promptly afterward rotted.

I was surprised by the different views here so I googled “textiles recovered from the Titanic” and the sites I found spoke of the known corrosive effects of salt water; I was relieved to find I’m not crazy.:-)”

 A person from the US said: “I wonder if the water melting off glaciers has an effect? We know it has a climatic effect in that the cold fresh water that comes off the glaciers each summer is heavier and denser than the water in the Gulf current, so that it sinks, then flows slowly southward. That sinking action draws the Gulf current north and keeps the British Isles and France (among other countries) warmer than they would otherwise be. A gardening example is that the south of France is at about the same latitude as the US state of Maine, which means they have the same amount of light at the same times of year but oh, what a difference in the plants that can be grown in the two places!

So what I wonder is if the seawater around Norway and Sweden is less salty than in other parts of the ocean and if that might have an effect on wool scoured in it.

Or perhaps the damaged fleece you have was already damaged while on the sheep for some reason and would have been useless for textiles no matter how it had been washed.

So many questions and so little grant money to answer them!”

The discussion about salinity in sea water continued for a while. This is part of one of Barbro’s posts on the matter: “The Atlantic is saltier than the brackish Baltic Sea, and during the summers lots of fresh water flood out from glaciers and rivers. It was probably during the late spring, summer and autumn they washed their wool and woolen clothes. Scandinavia including Finland has thousands of rivers flooding out into the Baltic Sea each year. I can sea rivers in the maps of the Baltic countries also, and Germany and Poland. It depends on in which part of the sea the shore is whether the water is polluted or not. There is also water from the Atlantic coming in all the time.” […]

A Norwegian informant brought up the question of woolen sails. He said the Vikings couldn’t have gone to all the places they did without the sails.

The sails were not discussed any further, as it seamed to take the discussion away from the question of wool being washed in sea water. I remembered that sails where impregnated with tar, which I today found to be true: found to be true.  Hence sea water could not be the secret behind the efficiency of Viking sails. Here’s another article about Viking sails:

There was some discussion about North Ronaldsay sheep. The sheep get soaked in sea water when eating sea weed. They get rinsed in rain, over and over again. They or their wool don’t seem to suffer from it. By a funny coincidence I got a sample of North Ron from North Ronaldsay yesterday. I washed it today, and I think it smelled – salty. I probably hallucinated 🙂

North Ronaldsay fleece from North Ron. Like sea water

North Ronaldsay fleece from North Ron. Like sea water

The discussion about why wool (and clothes from other materials) suffer from sea water in some parts of the world and not (at least not very badly) in other parts went on for a while. The conclusion of this seems to be the concentration of salt in the sea water, and also how long the wool has been in the water. The question isn’t by any means solved.

On Friday afternoon I had an e-mail from Annika Michelson, who’s employed in the KnowSheep project. She says that sheep in Estonia have been washed in both sea water and lake water. Today highly alkaline water that probably contains some sort of minerals from wells is used. The sheep drink the brackish sea water and eat sea weed, which probably is good for them. On the other hand it’s been noticed that sheep in a little Estonian island have black livers in the summer (iron, Fe), which indicates they eat something with iron in it. They’re not harmed by whatever it is that causes it. If they are slaughtered later in the autumn after having grazed on other lands their livers have returned to normal color. She says “There’s still so much to research!” she says.

ETA 19 October: Annika wants to correct a misunderstanding: Sheep eats / drink something that makes Fe to deposit in the liver”.

Yes, you saw that: sea weed. So the sheep on North Ronaldsay are not alone.

And just now, when I was about to publish, another mail from Annika about washing wool on another Estonian island, Hiiumaa: When the ground is frozen and the first snow has fallen in the autumn, they lay out raw wool on the snow on the north side where the sun won’t shine upon it. When more snow falls they shovel it on the wool so it’s completely covered. Later in the winter more snow falls and they don’t have to shovel any longer. When the snow melts in the spring the wool is clean! And it’s soft and nice in every way. The project has tested the method at Lahemaalammas (site only in Estonian but with lovely photos of sheep and products) and it works fine. Friendly to the environment, very little work, and the nature does it for free. No mice or voles. The wool was put in mesh bags of the kind used for onions.

3. Chemistry

I don’t feel capable of summarizing the chemistry discussion, so I copy everything, pairing questions and answers. I call the participants (1), (2), (3), (4) in the order they first appeared.

(1) opened the discussion on chemistry: “Hi! I thought i’d come in and think about some of the chemistry involved here with this sea water and wool relationship.

First thing to note, is exactly what wool is. It’s a protein, so made up of amino acids with peptide (amide) linkages. Within the protein it’ll have hydrogen bonds, disulphide bridges mainly. it’s the interactions of the stuff in sea water with the protein fibers that cause a change or weakness to the structure on a macroscale.
Seawater is made up of quite a few things, in fact, most. mainly it’s chloride, sodium, sulphate, carbonate, potassium, bromide, flouride, etc. Loads of stuff. The ones that are going to make the difference are things like the flouride, carbonate, sulphate and chloride. This is mainly because in solution they’ll have come from their conjugate acids. That means pH will be partly dependant on how much of these you have in the sea. There is a way of calculating it, and pH, but that involves more maths, and might take a while to explain properly so I won’t for now (unless someone want’s me to… feel free to ask 🙂 ). Overall however, the pH of seawater on average should hover at around 8. Slightly alklaline in fact. You may get the bases acting as nucleophiles, and actually attacking the lanolin, hence the reason it might cut some grease. you’re more likely to get attack from Br, Cl and potentially some F, as well as attack from the limited amount of OH that’s naturally present in water. The only problem, is that you might also get attack of the protein. If that happens, then the cycle will auto catalyse itself, and you’ll start to exponentially break down the protein. That’s actually an entirely possible scenario as to why your wool is tender if it’s been in a salty environment for a long time.

I think it’s unlikely that the disulphide bridges are breaking down. It’d take quite a reducing environment to do that (you have to add a hydrogen.. i.e protonate, the sulfur to allow any sort of cleavage to occur). In the same way, i’m not entirely sure that there would also be any ionic interactions with the protein that are too significant.
There are probably other things that could go on, but in terms of cleaning and why your wool is fragile, I think what i’ve talked about is possibly the most likely. If you also want drawings or anything of how it might happen I can do that for you (assuming you want to know more about the science behind :)!)”

(2): ” [—]. I have a question: would sweet water with added shop/store salt be more of a risk of breaking down wool fibers than seewater (of any salt level)? Actually I have 2 questions ;-)), for I always wanted to know how much influence a detergent like Biotex has on the actual wool fiber. It sais on the label that it removes f.i. blood stains from the laundry – but these are proteins and so I thought that the wool might be affected as well?”

(1): “No problem.

good question! my original response would be no. You probably want to know why ;)!
Well. Basically the premise is that it’s the pH that is going to change. pH is dependant on hydrogen ion concentration (or rather H30+ but thats more of a technicality here). when you have salt from the store you’re talking about sodium chloride. that in water dissolves and you have floating chlorides and sodium ions. those aren’t going to cause a pH change really, or at least not much of one. If anything the chloride could buffer and resist any pH change, but i’m not totally sure that chloride is a great buffer. It’s also not a hugely strong nucleophile, as it holds it’s electrons a little too much to be able to donate them easily and hence attack the protein.

so second question… Yes is the answer. it will affect the wool. Blood amongst other things, is protein. Protein eating enzymes are labelled as proteases. these will also unfortunately break down the protein in the wool, as well as the blood stains. It’s in general a bad idea to use biotex or anything similar with wool or silk.
Cellulose might be ok, depends whether there is anything like cellulase, maltase, or amylase in there. All of those break down the bonds between the sugar molecules. I know that cellulose is obviously for cellulose, and maltase and amylase are for starch. I don’t know enough about the enzymes to know what their specificity is like.
does that help any? 🙂

(3): “Trivial question, James: you refer to chloride, bromide, fluoride. I’m used to hearing chlorine, bromine, fluorine.

Is this a US/UK difference (fiber/fibre), or a chemical difference?”

(1): “no not trivial at all in fact! It’s a chemical difference.
When I talk about chloride, bromide and flouride, what i’m talking about is the negatively charged ion as in Cl- (- should be superscript). chlorine on it’s own is Cl2 (subscript 2) as in the same as oxygen.
in fact, we do the same with oxygen… oxide :)!”

(4): “Minor point–I really don’t think the halides, except for possibly fluoride (and HF is a weak acid, so there would be less of it around) would saponify lanolin. Very weak bases. Hydroxide might, but at pH 8 and without heat you would have to wait a very, very long time to get appreciable saponification imo. There’s a lot more protein bonds around to attack than there is grease to break down.”

(1):  “True point. I was thinking about the bases more in terms of nucleophilicity rather than basicity. That kinda changes it a bit. F is probably the weakest of the three halides in terms of how likely it is to initiate nucleophilic attack I would have said? I see your point about more protein than grease, but bear in mind the grease would be coating the protein fibers. In that respect, you might get some saponification as well as protein degradation?”

(4): “Ah, right, and yeah, fluoride is going to be a really hard base. The tetrahedral intermediate you make is covalently bonded–you’re adding to the pi system, not breaking sigma bonds initially–and while I’ve heard of adding iodide to catalyze a SN2 reaction, I’ve never heard of anything like that to catalyze an addition-elimination reaction. I still think you’d have to soak a very, very long time to get appreciable saponification.”

(1): “Ahh that is a good point, I hadn’t considered that. After all, adding to a pi system is quite hard to do. The ester linkage is conjugated too, so that makes it even harder thinking on it. hmm in that case maybe rather than there actually being something breaking the ester down, it’s more a case of solubility. I know triglycerides are virtually insoluble in water, but maybe the dissolved solutes have an effect. I haven’t looked into solutions a huge deal yet (that’s part of this years modules), and i’m not really much of a physical chemist (i’m more inorganic :))”

Mini test, something for a party!

A spinner from Denmark did a mini test by soaking about 10 grams of raw Danish white merino (25 microns) with a high content of lanolin, and 10 grams of raw brownish-blackish-grey Swedish Finull (less lanolin) of approximately the same micron count in seawater from Vejle Fjord (salinity supposedly 2,8%) and another batch of the same wools in tap water (alkalinity approximately 17). Water temperature 13 C, time 5 minutes. Four women and four men tested the hand of the wools when dry without knowing in which water each had been soaked. Seven felt no difference, one did.

Note: the test was not intended to be a severe, scientific test! The spinner made it for fun, and she and her test persons had a great time doing it. Thanks for sharing, M!

Barbro’s comment: it’s obvious that 5 minutes in brackish sea water isn’t long enough to make any difference.

Estonian Native Sheep. Tricolor

Estonian Native Sheep. Tricolor

I’m so impressed by and happy for the spinning community! What an amazing group of people, and what a wealth of knowledge! Thank you so much everybody!

I finish with a comment from one of Sweden’s most renowned wool experts and spinners: she says we shouldn’t be afraid to use methods that have been found good by earlier generations.

I agree to that, and add that we also should use new knowledge. Wool is amazing. There’s still so much to learn.



  1. Deborah Gray

    I heard that in Puglia (southern Italy) sheep were (are?) driven into the sea to wash them before shearing, so perhaps the practice isn’t restricted to northern countries, but would be a practical solution in areas with little fresh water but access to the sea. Here in Scotland it rains so much our sheep probably don’t need to be washed prior to shearing but I will make some enquiries.

    • Barbro Heikinmatti

      Yes, I’ve read about sheep being washed in fresh water ponds, streams, and even being washed in a tub. There are, as you say, plenty of pictures and photos showing this, and also written information in many reliable sources, i.e. M. L. Ryder’s Sheep & Man, and Den svenska fårskötselns äldre historia.

      Wonderful presentation of pics, thank you!

  2. Imogen

    Fascinating! Thanks for this great article, I was considering doing a first wash of a wooden blanket off the loom in sea water but I wasn’t sure if there was any research, turns out you’ve done all the hard work!!

    • Barbro Heikinmatti

      Thank you Brita! By “lighter” do you mean the water from the glaciers stay on the surface of the salty water? Or that the sea water becomes more brackish than salty during the spring and summer? I would’ve thought that the water from the glaciers mix with the sea water due to the movement of the waves. I also thought that there’s not enough sweat water to considerably affect the salty water.

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