Does Merino Wool Shrink in the Dryer?

Wool has a reputation for being rough and scratchy, but merino wool is completely different. 

Soft and lightweight, merino wool is highly sought after and used for a variety of garments, including those worn next to the skin. 

Merino fibres are elastic, allowing clothing to keep its shape, even after many years. Merino wool also wicks away moisture, regulates body temperature and resists bacteria and odours. 

This means that you don’t have to wash merino garments quite as frequently as synthetic fabrics, but they will need to be cleaned periodically. 

When you do wash merino wool, you’ll also need to dry it, which raises the question of using a tumble dryer. 

Below, we take a look at whether you can put merino wool in the dryer and how to keep it in prime condition when being washed. 

 

Does Merino Wool Shrink in the Dryer?

Merino is a type of wool that comes from merino sheep most commonly found in Australia and New Zealand. 

Although it feels very different to some other types of wool, it retains some of the same qualities such as its ability to felt. 

Felting is the process which causes wool to shrink. It happens when the wool fibres tangle together, creating a denser material known as felt. 

Felting occurs when wool is agitated or wet and exposed to heat. The longer the exposure, the more tightly the wool will felt. 

Merino wool, like other types of wool, will felt when exposed to heat. Putting your merino wool in the tumble dryer will therefore mean it starts felting and will cause it to shrink. 

Most merino wool items carry labels advising that they should not be tumble dried. 

You might find some merino wool items can be tumble dried for a very short time on a low heat, but it’s risky if the label doesn’t say that it’s pre-shrunk and ok to tumble dry. If in doubt, don’t risk it. 

 

How Do You Unshrink Merino Wool?

If you catch your merino wool item before it’s shrunk too badly you might be able to return it to its original dimensions. 

However, if the shrinkage is severe, it will be virtually impossible to tease apart the felted fibres and stretch your garment to the size you want. 

Add a generous squirt of hair conditioner or fabric softener to a bowl of warm water. If it doesn’t mix well, you can add a small amount of washing up liquid or laundry detergent, but not too much. 

The conditioner or softener is key to relaxing the fibres and loosening up the wool so don’t skimp on this part. 

Place your shrunken merino wool item in the water so it’s fully submerged. Allow the garment to soak for up to 20 minutes. 

Don’t agitate the merino wool as this will have the opposite effect and will shrink it further, but you can gently squeeze it periodically to help the water fully penetrate through the layers. 

After 20 minutes, remove from the water and squeeze to remove surplus moisture before placing on a towel. 

Work carefully to gently stretch each section until it’s the size and shape that you want. If you can’t get it to the size/shape you want, you may need to return it to the water for another soak before stretching again. 

If you try to stretch it too far, too quickly you’ll ruin the elasticity and end up with a shapeless mess. 

Once you’re happy with the shape and size, allow it to dry while laid flat. When completely dry, wash it again to remove the conditioner or softener remnants and dry it while laid flat again. 

You should now have a merino wool garment which is back in the size and shape you want, and ready to wear. 

 

What’s the Best Way to Dry Merino Wool?

Merino wool is very robust when it’s dry, having an elasticity which makes it ideal for all sorts of activewear and clothing. 

However, when it’s wet it can be more fragile, and needs careful handling to prevent it from changing size or shape. 

As mentioned above, it’s not a good idea to use a tumble dryer with merino wool. The same applies to other sources of heat, such as a towel rail or radiator. 

You should also avoid hanging wet merino wool up as it can cause it to stretch and become misshapen. 

The best way to dry merino wool is to lay it flat, and not in direct heat or sunlight, and allow it to dry naturally.