Yarn from Milk?

Yarn from Milk?

Note: As of January 2021, Izzy Knits no longer carries Bellatrista's yarns.

We've been fans of Bellatrista's Milk Yarn for some time, and it's proven to be a big seller in our shop. But as we prepare to show it off at WeFF (Weaving & Fiber Festival) in Torrance, CA on May 19th, we thought it wise to learn more about how exactly a liquid (milk) becomes a solid (yarn) fit for crafting.

What we learned from Bellatrista's owner and primary dyer, Dale Washburn, was so interesting, we thought we'd share it with you. Here's a summary of everything you need to know about Milk Yarn, in Dale's own words. At the bottom of the post, you'll find pattern information for all of the garments shown below.


Milk fiber, or casein fiber, has been around for quite a while. It originated in Italy in the 1930s, and reached the height of its popularity in the late 30’s and early 40’s, when most wool textiles were being used for military uniforms. After WWII, milk fiber was sort of forgotten with the introduction of new, cheaper synthetic textiles (nylon, rayon, etc.) as well as the renewed availability of traditional wool. It's sort of come and gone over the years as a textile fiber, and more recently for hand knitting, but [hasn’t really entered the mainstream] for some reason.

Attributes of Milk Yarn

The first thing you'll notice is that it's incredibly soft and has a wonderfully silky drape. At trade shows, we keep a scarf in our booth knit with the bulky milk yarn. As people pass by, if we can just get them to touch it, they're hooked and will always stop and often make a purchase. It's priceless to see the look on people's faces when they feel how soft the fiber is. They literally "ooh" and "ahh". They don't want to put it down.

Beyond that, the way it takes color is pretty incredible. No matter how we dye it (like silk, it takes both acid dye and fiber-reactive dye), the colors just shine. It shimmers like silk, but the colors don't fade, even after wear and repeated machine washing.

Which brings us to strength and durability. Milk is as strong as silk. It's machine washable, so it's great for baby blankets, baby clothes, etc. Some people also claim the fiber has antibiotic properties and that the proteins are good for the skin. (I can't really verify that, but it is slightly pH negative, so likely antimicrobial.) The fabrics breathe well and wick moisture.

Milk Yarn—Pros

  • Color fast
  • Light fast
  • Soft
  • Machine Washable
  • Strong
  • Less expensive than silk or merino
  • Some people claim that it’s anti-bacterial (slightly high pH) and good for skin (high protein content)

Milk Yarn—Cons

  • No memory
  • Fabrics may ‘grow’ or stretch over time
  • Slippery to knit with

How Milk Yarn is Made

The process for manufacturing milk fiber is similar to the Lyocell process for producing viscose rayon from plant pulp, which reduces the use of toxic solvents and minimizes waste streams. The fiber is made from bovine dairy milk. It takes about 12 gallons of milk to make a pound of fiber (~100L/kg). Because the casein is extracted from dehydrated milk solids, mills can use waste milk that is spoiled or contaminated and not fit for human consumption.

The milk is first dehydrated/dewatered, and the casein is dissolved in an alkali solution. The solution is extruded through a very fine spinneret into a bath that neutralizes the alkali and blends the casein with acrylonitrile to produce the strong, fine fibers that can be spun into thread or yarn. The process has been certified “green” under the Oeko-Tex Standard 100 for international textiles, meaning that both the manufacturing process and the resulting fiber are environmentally benign and non-harmful to humans.(More details on OEKO-TEX can be found online.

Patterns shown above include:

1. MORNING GLORY TWIN SET by Therese Chynoweth


3. SEASIDE SHAWL by Karen Whooley

4. CACHOEIRA SHAWL by Susan Gehringer


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