Can Yarn Be Microwaved?

The microwave wasn’t made for fabrics, it was made for foods but the manufacturers weren’t having the same thinking as a knitter. Starting from yarn straightening to heating pads, and so many other surprising reasons why you have the thoughts on microwaving your yarn. 

Yes, you can microwave your yarn but this depends on the type of yarn fiber. Yarns come in different forms such as cotton, silk, linen, acrylic, wool, rayon, nylon, and others which are of two categories. Yarns can be microwaved but only those that are natural fibers are 100% microwave-safe. 

What Type Of Yarn Can Be Microwaved?

Yarns are of two categories, natural and synthetic fibers. Let’s run through the two types and see a list of yarn in these categories.

1. The Natural Fibers

Natural fibers are fibers that are spun into yarn gotten from plants, insects, and animals. Yarns in this category are all microwaveable or microwave-safe.

Yarns in this category are Wool, Camel, Yak, Qiviut, Mink, Alpaca, Ramie, Pineapple, Banana, Bamboo, Cashmere, Cotton, Silk, Linen (Flax), Llama, Mohair, Hemp, Tencel, and Angora. 

2. The Synthetic Fibers

Synthetic fibers are human-made fibers spun into yarn. Synthetic fibers are flammable and prone to melting which makes them microwave-unsafe. Also, if the yarn has a synthetic blend, it shouldn’t be put in the microwave.

Yarns in this category include nylon, polypropylene, acrylic, polyester, rayon, lyocell, spandex, viscose, and kevlar. 

Is Microwaving Yarn Safe?

Yes, it is safe to microwave your yarn but ensure to microwave a yarn that is 100% natural fiber with no blend of synthetic fiber. However, if there is an addition or a minus, as long as your yarns are plant or animal-made fiber, they are good to go in the microwave.

Why Do People Microwave Yarn?

Aside from the types of yarn that are microwave-safe, there are a few reasons why people microwave yarn. The followings are the reasons for such and the procedures involved in each process:

1. To Straighten Yarn

Microwaving yarn is a heat temperature process that gives the yarn stability, makes it neat, and also has other effects such as higher volume, temperature resistance, and anti-wrinkle. This microwaving process is best for 100% natural yarn fibers.

However, before you put in the entire yarn, first put in a small sample of the yarn to check its response to high heat temperature. If it is microwave-safe, loosely twist the yarn into a ball,  and fold. Then, put the entire yarn in a plastic pouch or bag and seal it. After, put it into the microwave and allow it to stay for about 20 seconds. 

Note: You do not need to add water to the bag or make the yarn damp. Also, in some cases, the yarn gets thickened as a result of the steam depending on the yarn type (if it is wool yarn, the steam makes it thick but the threads do not steam).

2. To Make Yarn Heating Pads

A heating pad is made to warm an aching or painful part of the body. There are three ways of making a heating pad using a yarn towel, yarn pouch, or bag with some other items like rice, barley oats, etc.

  • A Towel Compressor: soak two towels in water and drain out the water till they become damp. In the yarn bag, put one of the towels and leave it open. Then, put it into the microwave and high heat for about 3 minutes. After, removing the bag, seal the bag and wrap it in the second towel. Apply the heating pad to the sore or aching spot to stay or put and remove. The heat should last for about 15 minutes or more. 
  • Using Rice: in a yarn bag or pouch, add rice into it. At the top, leave enough room to close the opening. Then, put it into the microwave and heat it for like 2 minutes. After the rice has been heated, it creates a great heating pad that you can place on the sore area. If it however gets cold, repeat microwaving it.
  • Using Barley Oats: in your yarn pouch, put the barley oats and add dried or florals for soothing scents. Then put it into the microwave and leave it to heat for about a minute. After, remove it and place it on the aching spot.  

3. To Make Yarn Bowl Cozies

Do you like your food extremely hot? Then, Bowl cozies are great ideas to hold your plates through the hot and cold moments. It is known as an insulated holder crocheted or knitted with yarn to serve as bowls that can be heated in microwaves. Put your food plates into the bowl cozies and put them into the microwave.

4. To Dry Wet Yarn

Microwave drying yarn is one of the best methods to preserve yarn products to retain their original features and produce yarn products of high quality. The method of drying wet or damp yarn with a microwave is to turn the machine into a heat medium to allow heat to penetrate the moist yarn. Unlike the hot air drying process, the microwave has a low influence on the original surface of the yarn fiber, the single fiber of the yarn, and doesn’t allow it to bleed. 

In a plastic pouch, put in the damp yarn and turn on the heat setting to a medium temperature. Then, leave the yarn for about 2 minutes. After, bring it out and allow it to cool.

5. To Dye Yarn

This might sound so ridiculous, but microwave dyeing of yarn is a fast and effective process of dyeing yarn fibers in small quantities. Acid dyes are used and this method is ideal to create colorways samples for small projects. It is also used to touch the white spots on yarns that are hand-painted.

The microwave dyeing process gives the simple tip for having a classic, lively, exciting, and beautiful yarn that is hand-painted from the loosely wound yarn center to the pull balls of yarn. To dye and microwave your yarn, the following are guides to put you through and also precautions to keep you safe:

6. Dyeing Process

Using your knowledge of the regular dyeing process, the first thing is to presoak your yarn into an acid solution of white vinegar and water (if it is an animal fiber yarn) or plain water (if it is a plant fiber yarn) – check the natural fibers list to know better.

There are two methods of microwave dyeing: you can remove the presoaked yarn and dye it or put it directly in the microwave machine. 

 If you’re dyeing before microwaving

  • Drain out a little of the wetness from your yarn using a towel. Pour your dye stock into a bowl and put the yarn. 
  • Then, cover the bowl with a lid and place it gently in the microwave. Set to heat for about 2 minutes.
  • After, remove the bowl and allow it to cool for about 2 to 3 minutes.
  • You can now turn the yarn ball and add your dye stock choice in about four places at the top of each. Then cover the bowl and return to the microwave to set the dye for about another 2 minutes. 

If you’re microwave drying before dyeing

  • Now, into your microwave machine, put the presoaked yarn. Your microwave machine is a dish with a lid on top or another option is to fold the presoaked yarn into a plastic bag or pouch and put it into the microwave. This helps to trap the steam for effective dyeing.
  • Then, get rid of the wetness. Do not remove all the water, the yarn must be damp to prevent the colors from bleeding (but you can leave it soaking wet if you desire the bleeding)
  • Now, remove the yarn from the microwave and dye it. 
  • After, place the dyed yarn into the microwave and leave for about 3 minutes.

For both microwave-dyeing processes, kindly take note of the following:

  • The type of dye you should use depends on the type of yarn fiber (check more about yarns and their dyeing process).  To dye your yarn, you can use a single color or do the hand-painting to dye your yarn in multiple colors. 
  • Do not use a microwave that has been used to dye to prepare food.  Also, water shouldn’t be left standing on top of the yarn. 
  • To know if your dye is set, check to see if the water in the bowl is clear. Once the dyed yarn is removed, allow cooling before washing to help the yarn absorb the dye completely. 
  • When washing, be careful to prevent the yarn from felting. Once you’re done, then you have successfully microwave-dyed your yarn. Isn’t it so simple?


Microwave-safe yarns are those made from natural fibers (plants and animals). Is it safe to microwave only natural fiber, if it is blended with synthetic then, it becomes flammable and risky to put it in a microwave, it will surely melt, burn, or even catch fire.

With this, you should get started and make use of your abandoned or old microwave for your yar to create things like heating pads, and hot pads, straightening your wrinkled yarn and dyeing easily.