How Do You Reuse Old Sweater Yarn?

The yarn has been used for centuries for producing all kinds of clothes and other textiles, whether it’s used in sewing, crocheting, knitting, weaving, embroidery, or even ropemaking.

With such an overabundance of knitwear, it’s important to remember not to waste any yarn. Purchasing yarn can also be expensive – especially if you’re looking to avoid even a hint of synthetic fibers!

Reusing old sweater yarn and yarn from other knitwear is surprisingly easy. It can help reduce your carbon footprint and support local charity shops and organizations.

Once you’ve found the perfect old knitwear, unraveling the yarn is as simple as following some steps, washing the yarn, and then dyeing it if you’d like to change the color or spruce it up a bit!

Is yarn environmentally friendly?

Yarn is made up of different fibers, usually wool, cotton, or polyester. Yarn can also be made using bamboo and hemp.

Other fibers used as yarn include:

• Silk
• Linen
• Cashmere
• Nylon
• Acrylic
• Rayon

Often, yarn is made using synthetic and natural fibers together, to reduce the cost of using natural fibers, add more durability to the yarn, allow it to be machine washable, and make the yarn lighter.

Yarn can even be made from the leftover fabric during T-shirt manufacturing. Known as T-shirt yarn, its popularity has risen in recent years, especially as brands have begun recycling old T-shirts into yarn.

An article in Natural Life Magazine in 2010 even gives steps on how to transform your old T-shirts into yarn.

With so many different fibers, it’s hard to answer whether the yarn is environmentally friendly or not, because there are major differences between them.

Wool and cashmere are environmentally friendly, as they’re natural fabrics, but the treatment of sheep and goats can make them unethical at best. As animal fibers, wool and cashmere also aren’t vegan.

Cotton is one of the most sustainable materials on the planet, but cotton plants require a lot of water, and cotton plantations often use pesticides that run-off into nearby rivers and groundwater. While environmentally friendly, cotton yarn might not be eco-friendly enough for most people, especially when brands aren’t transparent or don’t use organic or recycled cotton.

The worst yarn fibers are unsurprisingly those made of synthetic fibers: polyester, nylon, acrylic, rayon, and blended yarn (where natural fibers are combined with synthetic fibers).

Dye used in yarns is also environmentally unfriendly, and the amount of water used in the dyeing doesn’t help – unless you consider how much it helps pollute the environment!

The most sustainable yarn fibers are organic, undyed or naturally dyed, and recycled. Finding affordable yarn that meets all three of those standards (and isn’t greenwashed) is getting easier but isn’t widely available.

Even purchasing recycled polyester yarn is better for the environment, but there is something you can do to help the environment and use environmentally friendly yarn: reuse yarn from your old sweaters.

Can you reuse yarn from sweaters and other knitwear?

You can reuse yarn from your old knitwear, especially old sweaters – just like generations have done before us ever since the yarn was invented!

Unraveling knitwear and reusing its yarn is frugal and eco-friendly. You could even purchase old knitwear from charity shops and thrift stores, especially if you spot any holes or defects.

According to Tin Can Knits, the right knitwear to use:

• Must have been knit to shape, not cut to shape
• Doesn’t have seams like inside a T-shirt (look for easy-to-unpick seams that look like a column of Vs)
• Has spaces and rows when stretched in all directions

How do you reuse old sweater yarn?

There are many tutorials with step-by-step photos showing how to unravel old sweater yarn. After you’ve unraveled your knitwear and washed the yarn, it’s ready to be reused!

Tin Can Knits’s tutorial demonstrates how to unpick from the seams, pull the yarn, and start unraveling. It also covers soaking and dyeing the yarn.

One of the best tutorials is by Craft Stylish, which uses a bulky yarn sweater from a thrift store throughout its steps. Using just the thrift sweater, a seam ripper, scissors, water, and dish soap, you can unravel a whole sweater to knit your next project. Or, as Craft Stylish suggests, a holiday gift!

There are also video tutorials – like this one by Ashley Martineau – which show you how to unravel sweaters.

If you find that the yarn has too many kinks, you can follow Julie Kundhi’s instructions on soaking yarn and hanging it up to dry with a weight to straighten the fibers.

If you find that the sweater you have has a seam that has been machine-stitched, you can cut around the seam to remove it. The yarn around the seam may be short, but you can reuse this for smaller projects or when only a little color is needed in your knit pattern!

You can also reuse any off-cuts and seams as stuffing to make unraveling completely zero-waste.

How to dye yarn

You can dye yarn with eco-friendly ingredients, even ones you already have at home!

You’ll need:

• A container you don’t mind getting stained, big enough to soak all your yarn in – set it aside only for craft projects so you don’t contaminate food!
• White vinegar
• Gloves
• Spoons and cups
• Cling film or a second container
• Natural dye – like food coloring, onion skins, avocado skins, elderberries, nettles, etc.
• A heatable pot for solid colors you can put on the hob

Yarn should first be washed in an acid bath using white vinegar. This helps clean the yarn and allows the fibers to open so that the dye can seep into it.

Add around 3 tablespoons of white vinegar per skein to warm water, which should be enough to soak and cover all the yarn.

Many dyeing instructions recommend using mordants, which are minerals that can often be harmful to your health and are almost always best to avoid using to avoid polluting water systems. Mordants are most used for protein fibers like wool and silk, but the white vinegar bath should be fine.

Plant-based fibers like cotton and linen benefit even more from the white vinegar bath because vinegar is a fixative that can help set the dye.

After soaking for 30 minutes, rinse the yarn under running water and place it in a different container or on top of cling film.

There are other ways to dye yarn, but the following instructions work for giving the yarn a solid color:

• Fill up a pot with enough water to cover your yarn. Add your chosen natural dye and let it soak for a few minutes. Your natural dye could be food coloring or even vegetable skins leftover from yesterday’s meal prep!
• You need to fix the dye with heat, so place the pot on the stovetop and let the water come to an almost boil. Gently stir the pot without felting the yarn, allowing the dye to disperse.
• Take the pot off the heat and let it cool to room temperature. Once cool, rinse the color out in cold water and ensure the dye is fully rinsed. Be careful not to feel the yarn and only use cold water.
• Once you’re certain all the color has been rinsed out, hang the yarn on a line or airer to dry.

Different dyes require different methods, so have an idea of what color you’d like to achieve and what’s available to you. Food coloring is one of the clearest ways to get specific colors, but it might not always be the most eco-friendly.

What can you do with old yarn?

If you have too much yarn or yarn you just don’t know what to do with, there are ways to use it up. Sometimes you even have leftover yarn which isn’t enough for a full project!

What can I make with yarn scraps?

Yarn scraps and small amounts of leftover yarn can be used to make all kinds of crafts, or even add to future crafts.

You can use yarn scraps for:

• Seaming yarn
• Contrasting edges
• Pom poms
• Stuffing
• Yarn for mending old socks and knitwear
• Embroidery – especially for pillows or small knitwear
• Experimenting
• Stitch holders
• Tying gifts instead of ribbon
• Knit flowers
• Making small animals or toys
• Tassels
• Braiding

Can you recycle yarn?

Yarn isn’t easily recycled. Instead, you should donate yarn, especially wool yarn, to charity shops, textile recycling organizations, or community groups. These can then be used up by other people.

Maybe even set up a yarn exchange network to swap with local knitters!

Can yarn get moldy?

Yarn can become moldy, especially if you store it in plastic bags.

Getting rid of mold in yarn can vary greatly depending on whether the yarn has mold spores or not, as well as the type of yarn. Forums like KnittingHelp are the best place to go for the advice!

To store yarn properly, you should:

• Hang yarn in closets or put it in old pillowcases in places out of direct sunlight
• Avoid storing yarn in damp basements or hot attics
• Check for moths regularly and tackle them before they lay eggs