How to Un-Shrink a Wool Sweater (& Tell If It’s Possible)

Is it possible to un-shrink a sweater? If your favorite wool sweater (or other garment) shrank after a hot water wash or dryer cycle—or both, you may be able to fix it. Use these tips from fiber-expert Kristi Porter to see what can be done to restore it.

This post will show you how to assess the damage, and (hopefully) get that sweater back to normal. Otherwise, you can turn your felted sweater into a pet bed.

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Unshrinking Sweaters

Is There a Way to Unshrink a Sweater?

I consulted with my friend Kristi Porter, author of four knitting books and a long time contributor to Knitty.com, including a column called Frankenknits about repurposing knits. Kristi definitely knows her fibers, so I knew she’d be able to help.

This tips work for various wool fibers including cashmere, merino, and angora.

We’re talking sweaters here but the same tips apply to any wool garment including hats, scarves, mitts, jumpers, and so on.

Here’s what you need to determine first.

Is It Shrunken or Shrunken and Felted?

The first step is to determine the extent of the damage.

Did the sweater just shrink down a bit or are the fibers actually felted?

• If the wool has just shrunken down a bit, there’s hope.
• If the fibers are felted (i.e. shrunken, and tightly schmooshed together), you’re out of luck for unshrinking. Though there’s plenty of other projects you can make with the felted material (see below).

Felted Test

There is no specific test to determine the degree of feltedness other than your own observations.

Examine the garment:

• Can you still see individual fibers? Or is it all fuzzy with no real distinction between fibers?
• When you gently pull a small 2″ square section in opposite directions, is there any give?

Tightly felted knits have no stretch left which means the fibers can break when pulled. At this point you have an unwearable sweater, so you can either experiment with unshrinking or proceed to fully felt those fibers and use the fabric to make something else. Or give it to someone with a tiny body and long arms. Or your cat.

Multi-Fiber Items

What if the sweater has several different fibers in it?

It’s impossible to give advice on all the possible variations (various natural and synthetic fibers in varying percentages). You’ll have to decide if you want to experiment with unshrinking or intentional felting.

How To Unshrink a Wool Sweater

Remember, this will only work if the sweater is made from wool and has not felted.

What Products Can Help Unshrink Wool?

The two recommended products are Soak or Eucalan.

1. Fill a clean basin or sink with warm water.
2. Add wool wash (like Soak or Eucalan) according to product instructions.
3. Gently add garment and press it into the water. Do not stir or agitate at all.
4. After 20 minutes, drain the water with the garment still in the basin. Do not rinse.
5. Gently press the water out of the knit, but do not squeeze or wring. When you pick it up, do so gently from the bottom.
6. Remove excess water by rolling in a towel or spinning in the salad spinner (So effective! Your knits will dry twice as fast!).
7. Lay the garment out and gently stretch, paying attention to any seams because that’s where you’re going to hit your limit on how much you can stretch.
8. Don’t overstretch the sleeve width, for instance, if the armhole insists on staying small.
9. Keep flat until dry.

Drying Tip

• Don’t put your knits outside to dry in direct sunlight! Drying knits outside on a picnic table is great for air circulation and really speeds up the process, however, some dyes used on yarns are enormously photosensitive and can fade or darken over a couple of hours! Cover your knits with a sheet or tablecloth to avoid damage.

Can I Use Other Products?

• You may see things like baby shampoo, fabric softener, and hair conditioner recommended for washing or unshrinking wool. These are not recommended. Stick with a product made specifically for wool fibers that does not require rinsing.

Wool Garment Care Tips

If you want to avoid this problem in the future, these tips will help.

• Avoid frequent washing of wool garments. A workaround with sweaters or tops is to always wear an undergarment like a t-shirt to absorb any sweat or body odor.
• If the label says to dry clean only, do so.
• If washing at home, only use a gentle product like Soak or Euclan.
• For washing machine, use delicate cycle.
• When handwashing, handle the fibers as little as possible.
• To dry, roll item in a towel and apply gentle pressure. Never use a dryer or hot, direct sun.
• Store away from moths. Wrap in tissue paper to absorb odors.
• If you suspect moths or moth larvae in the garment, place in large freezer bag and chill below freezing for several days to kill the larvae.

Trivia: Very few of the 150,000 moth species worldwide will lay their eggs on wool garments. The adults don’t eat the wood: it’s the larvae that chew on it.

What Causes Felting?

Almost any animal hair will felt. If you examine a strand of your hair you’ll notice that your fingers will glide smoothly down the strand but squeak or catch going “the wrong way”.

This is because hairs are covered with little tiny scales.

For a fabric to felt, the little scales on the hairs need to be opened up, then, as the hairs rub against each other, the little scales stick together and get the hairs all tangled and stuck like velcro, pulling the hairs closer and closer together.

Felting happens best with moisture, temperature shifts, and agitation. A high pH level (which soaps can cause) is another factor.

You can see how a trip through the washer with a hot wash, cold rinse, lots of agitation, and detergent is sure to shrink your sweater!

Repurpose Ideas for a Felted Garment

Once something is really felted, you can treat it like fabric and cut and sew wherever you like.

You could make:

So, what did we do with our felted sweater?

I made it into a bed for our pet rabbit.

~Melissa the Empress of Dirt ♛