What is Milk Cotton Yarn? And How Is It Produced?

Have you ever heard about milk cotton yarn? Or are you just heck, what is milk cotton yarn?

Well, today, I would like to share with you how I came to find out about milk cotton yarn and try to answer some questions, such as how do you get from milk to yarn? Or is it really an eco-friendly and sustainable fiber?

It All Started with Some Second-Hand Yarn

Some months ago, I was searching for second-hand yarn deals on the Facebook Marketplace. I sometimes do it because well, why not? I am a regular yarn addict after all! So, that day I found a nice lady from Den Haag who was selling some yarn in the cutest colors. She was advertising the yarn as “Milk Cotton“, and assuming that it was just cotton yarn, I went ahead and purchased it.

When I received the yarn, it was such a beautiful surprise to see how incredibly soft and squishy it was. It was kind of difficult to believe that it was pure cotton.
From touching the yarn, my guess was that it was a mix of cotton and acrylic.

However, since the label was entirely in Chinese, it was difficult to really find out the exact composition.

So, I asked Google. I scanned the text in Google Translate, and Google translated it for me.

The result was:

50% long-staple cotton, 30% of silk cotton, 20% milk cotton, and 10% of moisture regain

What is Milk Cotton Yarn? by RaffamusaDesigns

Obviously, the last 10% is not a component of the yarn. Instead, it is an indication of the amount of moisture present in the dry material.

So, overall, the label seemed to only mention milk and cotton as ingredients of this yarn. Which got me even more intrigued.

What is Milk Cotton Yarn?

After a quick Google search, I found that milk is indeed at the base of the production of milk cotton. To be precise, milk cotton is derived from the casein present in the milk.

If you’re not an expert, casein is a general name for a group of slightly different milk proteins, which, altogether account for the vast majority of milk proteins.

Most web resources talk about milk cotton as a soft fiber with bacteriostatic, breathable, absorbent, thermo-regulating, and hydrating properties.

Milk Cotton Through the Years

The production of milk cotton first started in Italy and in the US in the early 1930s. At the time, it was possible to buy milk fibers under the commercial names Lanital, Merinova, and Aralac.

The peak of the popularity of milk fibers was up until World War II. After that, the production of fully synthetic fibers took off and milk fibers were put in a closet.

In more recent years, milk cotton is living a new revival. There are mainly two reasons why milk fibers are living a second life today.

The first one is that milk cotton is hypoallergenic. So, many people with allergies seek pure milk textiles as an alternative to wool and other fibers.

Eco-Friendly and Sustainable

The second reason why milk cotton is living its new popularity is that its production is 100% sustainable.

In fact, since 2004, the milk fiber industries have the Oeko-Tek Standard 100 certificate. Having this certificate means that the process that they perform has no impact on the environment.

Since I have a green heart myself, I was very excited to read about this.

However, always wanting to find out more, I was curious to know how this 100% sustainable process makes possible to go from milk proteins to yarn.

So, I did some more research on the web to try and find out as much as possible about the production of milk fibers.

How is Milk Cotton Produced?

As we already said, milk cotton is derived from the casein proteins of the milk. However, although milk proteins are natural products, milk cotton is not entirely a natural fiber. Because casein is not a fiber, there must be a chemical process to transform it into one.

The Italian chemist Antonio Ferretti first invented the manufacturing process of milk fibers around 1936. Almost at the same time, also in the US, manufacturers were producing similar fibers like the ones by Mr. Ferretti.

You can read more about the production of milk fibers in the patents protecting the initial invention.

In short, the process starts with the denaturation of casein in an alkaline bath, usually an aqueous solution of urea.
If you are not familiar with proteins and have no clue what “denaturing a protein” means, here’s a quick example. You can think of a protein as a beautiful skein of yarn, properly folded, and with a determined shape. Now, if you leave your cat/dog or little kid alone with the skein for less than a minute, you might go back to find a pile of deform wool. Well, that’s the equivalent of a denatured protein!

Back to the milk cotton production. After the denaturation of casein, there is a coagulation step in an acid bath, which results in a very dense thingy. After some pressing, the dense thingy becomes fibers.

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Casein Fibers are Not Stable on Their Own

However, these fibers are not stable and usable just like that. That’s why there is an additional tanning step with aluminum salts and formaldehyde.

Formaldehyde does not exactly sound like a nice, eco-friendly chemical. All the opposite of that. Quoting the American Cancer Society,


The Modern Production Process

Luckily, the process is now a bit different and does not involve formaldehyde anymore. Nowadays, acrylonitrile replaces the formaldehyde.

Acrylonitrile is not the nicest chemical around either. You can read quite a lot about its health and environmental hazard in this document by the World Health Organization. Nevertheless, milk fibers are not the only ones that require acrylonitrile for their production. Basically, the production of all acrylic fibers makes use of acrylonitrile. Does this make it less bad? To me, it rather raises another question that “are acrylic fibers environmentally sustainable”? But that is going to be for another post.

Back to the production of milk cotton. One last thing to mention is that in the modern process, zinc replaced aluminum, which explains the bacteriostatic properties of milk cotton.

Milk Cotton is a Semi-Synthetic Fiber

After reading more about these production steps, it would be more accurate to define milk cotton as a semi-synthetic fiber.

Is Milk Cotton Really Eco-Friendly?

Recently, several producers claimed that they figured out a milk cotton production process that does not include acrylonitrile. A process that does not involve acrylonitrile would actually be eco-friendly and sustainable. However, nobody made their natural process public, so it is difficult to know the difference with the old process.

So, before we can answer the question if milk cotton is really eco-friendly, we will have to wait until the new process is shared with the public.

Concluding Remarks

After discussing the entire production process, I still have some more fundamental questions regarding the sustainability of milk fibers.

In particular, I wonder how sustainable can it be to use milk for the production of yarn and fabric?

For now, milk fibers are only a niche product. However, if more people were to buy milk-based clothes and fabrics, should we worry about the amount of milk that we would need to keep up with higher market demands?

In one interview with Bio Market Insights, the CEO and founder of Qmilk Anke Domaske stated that the fiber that they produce only uses waste milk proteins. So, they do not subtract any milk from the food chain.

I guess this is a good consolation. Nevertheless, shouldn’t we aim at reducing milk consumption overall?

I’d Like to Know Your Opinion

Well, I am going to stop wondering and asking questions for now. Please, leave a comment below to share your opinion about milk cotton.

Where Can you Buy Milk Cotton?

In case you would like to try out some milk cotton, I found that Rowan offers some Milk Cotton Fine.

For the rest, it seems to be very difficult to purchase in Europe.

Since most producers are located in China, they either do not deliver to Europe or are not entirely reliable.

I also found some milk cotton sellers on Etsy as well but the shop reviews were not very encouraging.

So, my suggestion is to search for some local sellers that you trust.

Further Readings

For some further reading on milk cotton, I suggest to you this blog post by Exchanging Fire, and this article by Boris Hodakel on seport.com. Both are extremely useful and knowledgable resources.

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13 thoughts on “What is Milk Cotton Yarn? And How Is It Produced?”

  1. Thank you for the in depth post. I too have the one’s with the Chinese wrapper. I like milk cotton for kitchen projects. It is actually very absorbent, and the color stays very well. I have had a dishcloth that is a year or two old, and it hasn’t faded at all. I also like that it is so soft.

    • I’ve also been using it for basically all my potholders and I love it! I just really wanted to know what and how it was made so I went to look for all this info. I’d say that the conclusion is that it is safe for potholders as long as it is made from pure casein fibers. Of course it’s not fine if it is only used to coat acrylic or other synthetic yarns. Anyway, did you buy yours online? I saw some very beautiful colors of that same yarn on an online shop from Cyprus and I absolutely would like to get them. However, because of this corona crisis, they’re not delivering to the NL at the moment. I’ll have to try again after life goes back to normal. 🙃

      • I agree. I look at eBay for “yarn lots”and people auctioning off their stash. You might find some there. I have the same problem essentially. I only have a little bit of pink, and some neon green left.

    • Hi Kim,
      so yes, urea is present in the pee of animals, including humans, because it is the molecule through which we get rid of the excess nitrogen in our bodies. However, despite it is present in urine, urea is nothing gross. Consider that the compound that is used at an industrial level does not come from pee at all but it is produced chemically as a pure molecule. If it can be somewhat reassuring, urea does not smell of anything in particular and it is not the compound that causes the smell of pee (the smell is caused by other molecules that we eliminate in the pee). In fact, urea has got a lot of applications in the industry, in agriculture (as a fertilizer), and it is also present in many skin lotions because it helps to hydrate the skin.
      So, no worries, there is no urine in the yarn! 🙂
      I hope this helped.
      Have a nice Sunday,

  2. You can purchase milk cotton from various stores within the website aliexpress.com. Have ordered other types of items on that website and have received products successfully, but delivery can be slow–90 days or more with the free shipping option for some products. If you pay more for shipping for an item delivery is more reasonable.

  3. Hi!

    The milk cotton, is it suitable for knitting or only suitable for crochet?

    [NL] Is Melk katoen geschikt om mee te haken? Normaal gebruik ik 100% katoen (Scheepjes) maar ik ben heel benieuwd of deze garens ook fijn haken? Wellicht heeft iemand hier ervaring mee.

    • Hi Suus, milk cotton is perfect for both knitting and crochet! It is extremely soft, so it is ideal for making many things from garments to kitchen towels!
      With the current production process, I am not entirely sure it is the most eco-friendly fiber, but yarn production is not eco-friendly anyway.

  4. “50% long-staple cotton, 30% of silk cotton, 20% milk cotton, and 10% of retain moisture cotton”
    That’s 110%. Actually the last one means moisture regain rate.


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