Eleven Tests to Identify Mystery Yarn

When I hit thrift stores and garage sales, I’m always on the lookout for natural yarn from animals, whether it’s wool, alpaca, angora, mohair, or silk.  These natural fibers possess phenomenal qualities of keeping a person warm, even when wet.  Yarns from plant fibers, particularly cotton, do not.  And synthetic yarns aren’t much better.

Unfortunately, these natural animal fibers tend to be rather expensive—unless you can pick them up second-hand.  By then, the people selling them at their garage sales have forgotten what they paid, or in the thrift stores the employees there have no idea of their value.  Also unfortunately, often the yarn is no longer labeled.  And to complicate matters, there are some pretty good looking synthetics out there that mimic natural animal fibers in appearance and feel.  It can be quite difficult to distinguish between the imitation and the real thing.

How can you tell the difference?  And why do you want to?

Well, let’s answer the why first.  It can at least help you decide if you wish to read further.

As mentioned above, these natural animal fibers can keep a person warm, even if the clothing is completely soaked.  Virtually everything that is knit in this country comes from Asia, primarily China.  That supply line is going to be cut at some point in the future.  People are going to need to be able to knit their own hats, mittens, and scarves to keep warm.  Building a yarn stash now just makes sense.  And knitting is a great hobby for being able to relax, especially at the end of a hard day. 

Being able to differentiate between the good stuff and the cheap stuff to start building a yarn stash is an easy skill to develop with just a few tricks.  Also, this doesn’t just apply to yarn.  Sometimes you can find great clothing and accessories that are already knit.  You might want to re-use the yarn or re-purpose the sweater.

If you are not familiar with how the yarns made from different fibers feel, take a trip to your local craft store.  Run your fingers over the various skeins of yarn, paying especial attention to acrylic, cotton, and wool.  Also note how the skeins are wound.  Cotton tends to be wound much differently than acrylic or wool.  Wool is usually wound in shorter skeins than cheap Red Heart acrylic. 

Before performing any tests on the yarn, do the following.  It may save you some time.  First, if there is a label, read it.  It should have the fiber content listed.  Also, sometimes when people roll a skein of yarn into a ball, they will occasionally wind the yarn around the label.  Handspun yarn may have a small tag attached.  It will also indicate the fiber content.  Second, don’t assume that one fiber is automatically softer than another.  There are some extremely soft wools—some as soft as acrylic.  It’s been my experience that acrylic sweaters are often much softer than wool sweaters, though quite a few knitters will assert that wool yarn is softer than acrylic.  I’m not too sure about that.  Manufacturers are getting better every year at producing some very high end synthetic yarns.

So now imagine that you are at a thrift store or garage sale going through a pile of yarn and wanting to set aside the good stuff.  Here are some tests to help you differentiate between animal- and plant-based fibers, and synthetic and natural fibers:

• Reality test.  OK, this is my own observation from years of going through yarn at thrift stores and garage sales.   
• The vast majority of yarn in both places is going to be acrylic, your plain vanilla Red Heart yarn.   
• Cotton yarn will be a distant second after acrylic.
• Wool is almost as common as cotton.   
• Alpaca comes up only rarely.   
• I’ve never run across pure angora, silk, or mohair, but rarely some novelty yarn that includes some of these fibers will show up.   
• You can make chiengora (dog yarn) at home (or pay someone to do it for you), but I’ve never seen it at stores or second hand. 
• Break test.   This is the fastest test of all for distinguishing between acrylic and wool yarns.  It works best with fine or medium weight yarn.  It will be difficult with thicker yarns.  
• Pull several inches of yarn away from the skein or ball.  
• Taking an end in each hand, pull the ends apart and see if  you can break the yarn.  
• If you can't break the yarn or if is takes monumental effort, it's probably acrylic.
• If you can break the yarn without much effort, it's probably wool.
  
• Sniff test.  This will help distinguish between wool or alpaca and all other fibers.
  
• Soak a strand of yarn in really hot water. 
• Does it smell like a wet dog?  If so, it’s wool or alpaca.  (Angora and silk usually do not have that wet-dog smell.)
• Hair test.   
• Look closely at the yarn for hair.   
• Wool, alpaca, angora, or mohair may have hairs sticking out from the yarn.  
• Cotton, acrylic, and other synthetics are usually much smoother and less likely to have hair sticking out.  
• Novelty yarn composed at least in part by acrylic will sometimes have fibers sticking out to give it a fuzzy look.
  
• Super shiny or glittery test.   
• Natural fibers like wool, alpaca, and angora are much less likely to have sequins, glitter, or metallic thread.   
• Acrylic and cotton are very popular fibers to use with sequins, glitter, and metallic thread.
• Light test.  
•  Shine some light on the yarn.   
• Fibers such as wool, alpaca, cotton, and low quality silk look dull.   
• Mercerized cotton will reflect light, and high quality silk shines.   
• Some acrylics, particularly older yarns, sparkle when viewed up close. 

The following tests are also very helpful in identifying mystery yarn, but they can be a little difficult to perform outside the home.

• Burn test.   
• Work over a sink or bowl full of water, and make sure there is nothing flammable nearby. 
• Cut a length of yarn about 3-4 inches long.   
• Hold the yarn with a pair of tweezers in the flame of a candle or lighter, taking care not to burn yourself.   
• As the yarn burns, take note of the smell and appearance.  
• If it smells like burning hair (like when you burn your hair in the curling iron), it is animal fiber.  
•  If it smells like chemicals or burning plastic, it is synthetic.   
• Wool burns faster than acrylic. 
• Blow the flame out and let the yarn cool.   
• Examine the end.   
• If it is ash, it is natural fiber.   
• If the ash crumbles when you touch it, it is natural fiber.  
• If it is melted, brown or black, and hard, it is synthetic.  
• If it seems to be a little of both, it’s a blend of natural and synthetic fibers.
• Felting test.  This takes a little bit of time.   It will distinguish between wool and possibly alpaca, and all other fibers.
  
• Cut two pieces of yarn several inches long from the same skein.  
• Fray (single ply) or untwist the (multiple) plies of the yarn for a few inches.   
• Separate each piece of yarn into two halves or plies.  
• Cut one of the plies on each strand, leaving one long and one short.   
• Lay the pieces of yarn together end to end so that the short ends are touching.  
• Wet the longer ends with a spray bottle (or lick them).   
• Then roll and twist longer plies from each piece of yarn together between your fingers until the yarn dries.  
• If all goes well, the long ends will fuse or “felt” together, indicating the presence of natural fiber.   (If there is any possibility that the fibers are angora, mohair, or silk, longer sections of yarn will need to be used.)  
• If the yarn felts together, it will not pull apart easily, suggesting that it is wool.   
• If the fibers do not fuse, the yarn is synthetic.
• Bleach test.  
• Cut a 2” length of yarn.   
• Place it in a glass jar with a lid.   
• Add enough bleach to completely cover the yarn.   
• Replace the lid on the jar.   
• Fizzing of the yarn after a few minutes suggests the possibility that the yarn is animal-based.  
• Check the yarn in 6-8 hours.  
• If the yarn sample has disappeared, the yarn is animal-based.   
• If it is only slightly faded, the yarn is synthetic.  
• If the yarn looks ragged and weakened, it is a blend of natural animal and synthetic fibers.
• Wash test.  Some wool yarn has been processed into what’s called superwash—items knitted or crocheted with superwash wool can be washed in a washing machine and dried in the dryer.  
• To determine whether your wool is superwash, place a 4-6” length of yarn in an old sock and run it with a regular load of laundry through the washer and dryer.   
• Remove the yarn from the sock.  
• If it is a tangled mess, it is not superwash.   
• If it is still a single strand of yarn, it is superwash.
• Fiber test.   
• Ravel some of the yarn and remove some fibers.   
• Soak them in warm water, and let air dry.   
• Examine the individual fibers carefully, using a magnifying glass if necessary.  
  
• Wool and alpaca fibers usually have a distinct kink, called crimp, to them.   
• Suri alpaca and angora often do not.   
• Cotton, linen, bamboo, and silk are very straight.   
• Acrylics may be straight, or they may be manufactured to have a certain level of kink to them.  However, in contrast to the irregular crimp of animal fibers, the kink in acrylic fibers is very uniform and even.

Using one of more of these tests will help you identify mystery yarns and enable you to build a good stash of quality yarn for pennies on the dollar. 

Links to related posts:

Woolen Mittens  

The Advantages of Natural Fibers  

Spinning Yarn on a Drop Spindle

Spinning Dog Hair into Yarn 

How to Repurpose Wool Sweaters