Does Wool Shrink? How To Unshrink Wool?

shrink wool

You’re in the right place if you want to learn how to unshrink wool. Yes, it has happened before to all of us. Unfortunately, we’ve discovered the hard way that wool sweaters in particular don’t like washing machines and dryers. But fear not, there is a way to bring your favorite knit back to its former splendor (praise be!).

Nope, it’s not a myth, you really can reverse the old ‘shrunken jumper in the wash’ situation. Here is our simple how-to for unshrinking a wool sweater, along with some helpful wardrobe pro advice for avoiding a repeat occurrence.

If So, Does It Shrink?

100% wool can shrink if you put it in the right environment. All of the protein in pure sheepskin is animal protein. Small, pointed scales cover each strand. These scales on a sheep don’t tangle because they all face the same way. A wax known as lanolin that protects the sheep’s skin and prevents the wool from shrinking or tangling is also present on its exterior.

However, lanolin is removed and the protein scales are stretched and twisted until they are pointed in every direction during the processes that turn that raw sheep wool into threads, yarns, and fabrics. Scales are more likely to overlap and latch onto one another as a result of this stretching and twisting.

Scales that are already distressed by heat and motion latch on to one another. The garment contracts as a result of individual fibers tying together, drawing the fabric closer together.

There are no other fibers to prevent the wool from pulling together if a fabric or item is made entirely of wool. For this reason, handwashing or dry cleaning rather than machine washing is recommended for the majority of 100% wool clothing. Unless you’re purposefully shrinking it, you shouldn’t ever dry 100% wool.

How To Unshrink Wool

There’s really just one simple rule to remember when it comes to washing knitwear, regardless of whether it’s a mohair jumper, a cashmere cardigan, or your favorite wool dress: don’t put it in the washing machine or the dryer!

Your favorite wool sweater accidentally got put in the washer. Fear not, HowCast will show you how to restore your favorite knit item to its original state in just five simple steps:

  1. Fill your sink with lukewarm water and 1/3 cup of hair conditioner
  2. Add the jumper and let it soak for about 10 minutes
  3. Drain the water by removing the plug. Press the jumper against the sides of the sink once it is empty to rinse it out; do not wring it.
  4. The jumper can be dried by laying it flat on an absorbent towel, another towel on top, and gentle pressing.
  5. Re-stretch the jumper to its original dimensions.
  6. Lay out to dry naturally on an airer.

Alternately, view this instructional video for a more visual explanation:

Why Does Wool Shrink?

The most important query: Why do other fabrics come out of the washer in perfect original condition while wool actually shrinks after washing? Wool, it turns out, has a scaley outer layer, according to the National Cleaners Association. “The wool fiber contracts and the edges of the scales interlock as a result of heat, moisture, and mechanical action, which prevents the fiber from returning to its original position.” To put it another way, when you wash or dry something, the wool’s fiber shrinks in a way that prevents the fiber from allowing the fiber to expand outward again.

How To Wash Wool Correctly

The best way to avoid shrinkage is to hand wash each piece of wool separately in cold water with sunlight soap or soap flakes (if using flakes, make sure to dissolve them in hot water first).

  1. Start by soaking the object in cool, room-temperature water.
  2. Rinse the item three times under cold water and make sure to get all the soap suds out
  3. Then, lay the piece flat on a towel (ideally in the sun) to dry after gently pressing all the water out of it. Every single time, this method is flawless, and the shape of the wool is preserved.

Wool Shrinks How Much?

Wool has a significant capacity to shrink relative to its initial size. You can easily lose two or three sizes by drying your clothes. How much your wool will shrink, though, depends on a variety of factors.

Wool shrinkage and fiber quality are influenced by the amount of heat and motion. Wool will shrink more as a result of increased heat and movement. The less motion you use, the less the wool will shrink because heat alone won’t cause it to shrink.

The motion felts the wool as well. The texture of the wool is altered during felting in addition to its size. Wool fibers’ scales rub against one another during agitation. They lock together more tightly as they rub, creating a dense, fuzzy fabric: felt. Wool shrinks when it is felted, and once felted, wool cannot be unfelted.

This is the reason why a wool sweater may shrink slightly if it is accidently placed in the washer, but significantly more if it is placed in the dryer.

Additionally, the type of wool affects how much it shrinks. A wool fiber takes more heat and agitation to felt and shrink the longer and smoother it naturally is.

One of the most popular sheep breeds, merino sheep, have relatively long fibers of wool that lack a lot of natural crimp. Merino wool takes longer to shrink than shetland wool, which has shorter fibers and more crimp. A wool fiber will shrink up more the more it naturally curls in on itself.

Merino wool is most frequently used in commercial wool clothing and fabrics. If there is another type of wool present, it should be indicated on the fabric label or garment tag. If it doesn’t say, assume it’s merino wool and that it will shrink fairly easily.

Does Wool Shrink When Laundered?

If you don’t follow the instructions on the fabric tag or label, wool may shrink when you wash it. Wool shrinks depending on how it is washed, and how much it shrinks.

Wool shrinkage is not caused by water. As long as the water is at room temperature or lower, wool can be wetted without being harmed. The issues occur when the wool is stirred up in a warm environment.

Any wool can be washed by hand in cool water, but only some wool can be washed in a washing machine. The agitation of the washing machine can cause the wool to shrink even in cool water. It’s best to avoid washing wool unless it is superwash wool because the shrinkage isn’t always permanent (more on that later).

Wool that has been specially treated so that it can be washed without shrinking or felting is called superwash wool. The manufacturer will either coat the wool fibers or chemically remove the scales’ points. Both techniques reduce the likelihood of the scales catching on one another, which stops shrinkage.

In the washing machine, the soap you use can harm wool. Wool can only be cleaned with detergent or soap that doesn’t contain enzymes. If your cleanser contains enzymes, they will break down the fiber’s protein structure. The scales interlock more readily and shrink the fiber as a result of protein damage. The enzymes can also eat through the fabric to create holes.

In The Dryer, Does Wool Shrink?

Even if wool was chemically treated by the manufacturer to withstand the washing machine, wool shrinks in the dryer. Your clothes will still be dried by the dryer even on the lowest heat setting.

Shrinking will be reduced by reducing heat and spinning or tumbling. While felting the wool and resulting shrinkage may occur when spinning or tossing it without any heat, it won’t be as severe as if heat is added simultaneously.

Wool from the dryer cannot be adequately protected by the coating that shields superwash wool from harm in the washer. The coating is more effective against agitation than heat. However, a superwash wool garment’s superwash treatment deteriorates more quickly the more motion and heat it experiences.

A superwash wool garment might not shrink significantly if you dry it for a short period of time. However, it will shrink more the more you dry it. Wool that hasn’t been treated or super washed will shrink even more quickly.

Your wool clothing will last much longer if you air dries it. Utilizing a clean towel, gently squeeze out any remaining water before reshaping the item to its original size and allowing it to dry flat. Your clothing won’t warp, felt, or shrink as a result of this technique.

Wool Shrinks When It’s Wet, Right?

Wool won’t shrink if only water is used. When you immerse wool in water, it slightly expands because the fiber absorbs the water. As long as you don’t add heat or motion, it will expand to its original size as it dries.

Wool can shrink in hot water, but only if you also stir the wool. The protein scales become more prone to catching when heated, but they won’t catch without movement that causes them to rub against one another.

The most shrinkage occurs when heat and motion are combined because the heat causes the fibers to expand and the scales to lift, and the move brings the fibers into contact with one another.

The fibers can also expand in water, but if there is no additional interference, they will shrink back to their original size and shape when they dry. Consider this: sheep, which are the source of wool, are not harmed by rain. Sheep constantly get wet and dry off without changing the size or shape of their coats.

When wool is wet, it is more delicate than when it is dry. For washing it, cool or lukewarm water works best. The fibers will be more delicate the hotter the water is. The easier it is for fibers to tangle and shrink, the more delicate they are.

There’s no need to freak out if you get wet while wearing wool clothing or if your feet perspire while sporting your favorite pair of wool socks. The fabric won’t be damaged by the water by itself. Lay it out in its original shape to air-dry after using a clean towel to gently squeeze out the water. Once it has dried, it will be as good as new.

Merino Wool Shrinks, Right?

The fiber merino shrinks. One of the most widely used kinds of wool for clothing and textiles is merino. It is simple to dye and soft enough to wear next to your skin because of its long fiber.

Merino wool does not felt as readily as other types of wool, but if heated and agitated, it will contract. Many merino wool clothes are superwash, which increases their durability. The dryer still has the tendency to cause these fabrics to shrink.

Close up on woman’s hands knitting

Blends Of Wool Shrink Or Not?

Blends of wool may contract. Depending on how much wool is in the blend, they can shrink quite a bit. Expect about the same amount of shrinkage as with 100% wool if the wool content is higher than 50%.

The other fibers in the fabric will help prevent the wool fibers from blending in blends where less than 50% of the material is made of wool. In most cases, a 5% wool blend shrinks considerably less than pure wool. Your garment may shrink regardless, though, if the other fibers are also prone to doing so.

Due to their shared protein composition and tendency to shrink, other animal fibers behave similarly to wool in this regard. The least likely fibers to shrink are acrylic and man-made fibers, followed by plant fibers in general.

A garment should always be washed using its most delicate or particular fiber. Although it may be tempting, treating a wool/nylon blend like nylon will result in a shorter lifespan for the clothing item.

Even if your fabric blend doesn’t shrink when you wash it, using a high-heat, high-agitation washer or dryer setting can harm a wool blend. The elasticity of many fibers, including nylon and acrylic, can be worn out by heat.

How To Purposefully Shrink Wool!)

There are times when shrinking wool is exactly what you need. Perhaps the wool cap you wore every day of the winter is beginning to sag, or the cuffs on your favorite wool sweater have begun to sag.

A damp wool garment can be placed in the dryer for 3 to 5 minutes on the lowest heat setting to slightly shrink it. If you shrink the wool by hand, however, you will have more control over the procedure.

The garment you want to shrink should be immersed in hot water that has been poured into a large bucket or sink. Gently swirl the garment in the water while moving it around. After that, take it out, squeeze the extra moisture out, and lay it flat to dry.

As it dries, you can shape it with your hands by spreading out areas you want to be larger and drawing in areas you want to be smaller. To have even more control, dry the areas of the garment you want to shrink the most with a hairdryer set to the lowest heat.

Instead of using a clothes dryer, use a hairdryer so you can monitor how much the fabric is shrinking. You have more control over the process, which reduces the possibility that you’ll accidentally ruin your clothing or overshrink the fabric.

Wool: Does It Always Shrink?

The shrinkage is most likely temporary unless the wool has felted. If the shrinking was significant, you might not be able to restore your garment to its original size. To help repair the harm, it is possible to make the protein scales loosen.

Wool has memory, so no matter how you stretch, crinkle, or tangle it, the fibers will attempt to revert to their original length. Wool is an advantageous fiber for clothing and other textiles because of this characteristic.

You must reopen the fibers and loosen their hold on one another in order to reactivate the memory of a wool garment. The fibers will begin to rebound once the grip is loosened, returning to their original dimensions and resizing the garment.

Water, hair conditioner, and perseverance make it simple to reopen the fiber and loosen the scales.

Proteins found in wool fibers are also present in human hair. When you soak a wool fabric in water and hair conditioner, the results are similar because hair conditioner works by smoothing the protein scales in human hair. The conditioner can enter the fibers after being opened up by the water. The conditioner helps the protein scales lay flat rather than protrude by smoothing them out.

Your wool needs to be soaked in a solution of water and 13 to ½ cup of hair conditioner for 15-20 minutes in order to un-shrink it. After gently pressing out the excess water, spread the garment out to dry.

Rework and gently stretch the garment to the desired size while it is still wet. The freshly separated fibers will try to revert to their original length as much as possible as it air-dries.

The conditioner trick won’t help much, though, if the wool felts when it shrinks. The process of felting is perpetual. Although stretching wet felt might add a few extra inches to its length, it won’t shrink the wool back to its original size.

Wool Shrunk After Dry Cleaning?

Wool may slightly shrink if it is dry cleaned, but the bigger risk is that the process will harm the fibers and reduce the fabric’s lifespan.

In reality, dry cleaning isn’t dry. Although it doesn’t use water, it does make use of liquid cleaners, heat, and motion, which are more important. Dry cleaners use a machine that agitates and heats clothes. Although shrinkage from wool is generally minimized by professional cleaners, it is still a possibility.

More importantly, the solvents that dry cleaners use are frequently too harsh for wool. The proteins that make up wool, an animal fiber, are easily broken down by the enzymes and chemicals in a professional-grade cleaner.

Your pricey wool overcoat won’t be irreparably damaged by a single dry clean, but you should limit how frequently you dry clean wool clothing.

How To Wash Wool Without Shrinking It

Wool doesn’t easily hold odor or bacteria due to its natural porousness. A garment needs to be washed less frequently the farther it is from your skin. Wool socks may require washing after each use, but a wool overcoat or sweater worn under another layer will require far fewer washes annually.

Woolen clothing can either be dry cleaned or safely and affordably washed at home when necessary.

Even if your wool is superwash, you should still gently handwash it in cool water with a mild detergent before laying it flat to dry in order to prevent unintentional shrinkage. This procedure reduces movement and gets rid of heat.

As long as you use cool water and the delicate cycle, many contemporary wool fabrics are safe to wash. Wool must be stirred and heated in order to shrink. Although the clothes you wash in a superwash won’t shrink, they might lose their shape more quickly than if you handwash them.

Before washing wool, always check the fabric or garment tag. It will inform you if the wool is secure enough to wash. Wool should never be dried unless you want to intentionally shrink it.

Put your woolens in a lingerie bag or a plush pillowcase before washing them in the washing machine. Having an additional barrier will help keep felting at bay. Your wool clothing won’t chafe against all the other laundry if it’s in a bag. The extra protection may help the wool last longer even though it will rub against the bag.

8 Myths And Truths About Washing Wool

Wool is renowned for being a challenging fabric to clean and maintain. Are these rumors accurate, though? Several widespread misconceptions about how to care for wool were dispelled by a study done by Norway’s National Institute for Consumer Research (SIFO). Here are some of the most prevalent washing-related myths and truths to help you sort this out.

#1: Wash Infrequently, Air Out Often

True. Wool has the advantage of maintaining its freshness longer between washings than cotton or synthetic fabrics. The impact on the environment will be significantly reduced and there will be fewer washes throughout the life of the garment. Of course, this varies depending on how close to your skin the wool garment is worn. While cashmere wool sweaters don’t need to be washed more than a few times a year, merino wool long johns might need to be cleaned after a few days. even less frequently are woolen coats and jackets.

Allowing your wool clothing to air out overnight outside, preferably in humid weather, is a good idea. The time is right for washing if the smell of stale clothing does not go away after the item has been left outside for a night.

#2: Wool Garments Stain Easily

True. Wool clothing resists stains well. However, they are prone to staining. Clothing made of raw or organic wool is generally stain-resistant, but many other types of wool are more prone to stains, especially those that are difficult to remove, like berries, coffee, or chocolate. Wool is more likely to become permanently stained than synthetic fabrics, which also get stained easily but have a lower chance of doing so. Our best recommendation is to treat the stain as soon as it appears because waiting will increase the likelihood that it will become permanent.

#3: You Need To Use A Special Detergent

True. Only gentle laundry detergents designed for delicate fabrics should be used to wash wool clothing. Look for detergents with the words “delicate” or “suitable for wool and silk” on the label. Wool responds well to Steamery’s Delicate Laundry Detergent because it contains lanolin oil, which works as a conditioner and feeds the fabric’s natural protein fibers.

#4: Wool Garments Must Be Hand-washed

False. Some care labels may advise handwashing in order to preserve the fabric but not to preserve the seams or other sewed details. Machines can be used to wash wool on a gentle or wool cycle.

#5: Washing In High Temperatures Makes Wool Shrink

False. In hot water, wool can be cleaned. Even boiling is a possibility. Making sure the garment is still throughout the process is crucial. Only when the wool is moving around in the hot water will it begin to shrink. Always choose a wool or gentle cycle when using a washing machine because heat and motion are what cause the shrinking.

#6: Wool Garments Cannot Be Be Spin-dried

False. An old wives’ tale states that you must fold your wool sweaters in a towel and squeeze the water out of them in order to dry them. The SIFO study demonstrates that this is untrue, though. Wool can be spun dried, contrary to popular belief. There was no shrinkage with any of the three spin cycles that SIFO used—400, 900, and 1400 RPM. Even so, wool rarely requires a spin cycle greater than 800 RPM, so make an effort to reduce the amount of spinning.

#7: Knits And Wool Sweaters Must Be Flat-dried

False. Another widespread misconception is that woolen clothing needs to be dried flat on the ground while lying down. However, the SIFO study found that it is acceptable to hang-dry clothing on a hanger if it is sufficiently dry, as might be the case after a brief spin cycle.

#8: Wool Can Only Be Washed With Wool

False. Wool clothing can be washed with cotton or synthetic clothing. The SIFO study found an increase in the likelihood of a barely perceptible shrinkage (0.5%), but in this case, it is hardly significant. The study also found that washing wool clothing with other fabrics did not cause it to pill or attract more lint. Remember that the wool program is extremely gentle and best suited for only lightly soiled clothing. While it’s acceptable to add other kinds of fabrics, the washer shouldn’t ever be filled beyond 50%.

How To Care For Wool Garments

  • Always use an enzyme-free detergent. We recommend Steamery’s Delicate Laundry Detergent
  • Always dry on a low spin cycle, even if you’ve handwashed your garment
  • Hang-dry wool sweaters only if they’ve been spin-dried
  • Treat stains immediately when they appear
  • Air your garment and wash infrequently
  • Avoid filling up the washing machine to more than 50%
  • If your garment loses its shape or shrinks, stretch the garment with decisive and regular movements
  • Boiling wool for ten minutes will disinfect it. Keep the garment completely still during the process to avoid shrinking


Your cashmere and merino sweaters won’t shrink every time they get wet, but you shouldn’t throw them all in the washing machine either. You can maintain the proper size and shape of your woolen clothing for many years by avoiding heat and vigorous motion.

Have you ever unintentionally shrunk wool clothing? Comment below and let us know how you handled it.

Lucky Wong

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