Superwash wool is a special wool yarn that is machine washable.
Generally, wool fibers have scales and these scales bind to each other upon washing or blocking. With superwash wool however, either one or a combination of these two processes treats these scales. The first process is to shave off these scales from the fibers of the yarn through a chemical process and the second is to coat the fibers with polymer or resin as protective coating to eliminate the gripping factor such as felting.
Properties of superwash wool
Superwash wool tends to be softer. The scales from the wool fibers make the garment itchy on the skin so having these scales removed make the superwash wool soft and not scratchy.
Handmade items made from superwash wool are great for gifting. They do require low maintenance and easy care.
Shrinkage is not an issue with superwash wool.
Superwash wool tends to grow when it gets wet. With this in mind, it is great to use for knitting shawls and throws, items that are not critical with precise measurements to accommodate for the extra stretch.
Superwash wool is more expensive because of the extra process to achieve its “superwash” property.
How to Care for Your Superwash Wool Garments
To care for your superwash wool garments, machine wash in gentle cycle using cold water. Extremely hot water can destroy the protective layer of the yarn fibers and will actually make it susceptible to felting. It is recommended to use a soap or wash that is safe to use for wool. As with other delicate items, it is best to put your garment(s) in a mesh laundry bag while washing.
After washing, reshape your garment(s) and lay flat to dry, as instructed on the yarn labels.
Here is a tip.
It is always best to do a bit of research before using a foreign yarn you have never used before. They vary so much concerning composition and properties. I hope you can learn a thing or two about this lovely wool and have fun with it.