What Temperature Should You Wash Cotton At?

From bedding to socks to t-shirts, cotton is a type of fabric which is used for many things. Cotton can be dyed, mixed with other fabrics or used on its own, making it a very versatile option. 

It’s easy to accidentally destroy fabrics by washing them at the wrong temperature. So how should you handle cotton and what temperature should you wash it at? Here’s what you need to know. 

 

What’s the Best Temperature to Wash Cotton At?

As a general rule, it’s always a good idea to wash your cotton at the lowest temperature possible. This will help to keep the colours bright, minimise the possibility of shrinkage and extend its lifespan. 

There’s no single “right” temperature for cotton items as it all depends on whether it’s been mixed with other fabrics, and what the item is being used for. 

For the majority of cotton items, 40°C is a good temperature to use. 

It is possible to wash them on a slightly cooler wash if they are only very lightly soiled, but this won’t suit all items. 

Anything that has heavier soiling, odours, or slight staining should be washed on a minimum of 40°C. This will suit most types of cotton mixes, as well as 100% cotton.

Washing at a temperature of less than 40°C is good for your cotton and the environment, but it doesn’t always wash as well as warmer temperatures. If the cotton isn’t properly cleaned when being washed at 20°C or 30°C and you have to wash it again, it’s better just to wash it at 40°C in the first place.

Conversely, some items will need a wash that’s hotter than 40°C. This is particularly the case if it’s heavily soiled or stained, or you need to kill off germs. 

The NHS suggests using a temperature of 60°C to kill germs. The difference in performance between 40°C and 50°C is negligible, so it’s only really worth moving to 60°C if you need a wash that’s hotter than 40°C.

 

Does Cotton Shrink Every Time You Wash It?

As a natural fibre, cotton has the potential to shrink when it’s washed. This is because the individual fibres are stretched to make clothing or other items, and tension creates the shape. 

By absorbing water, the tension is relaxed, allowing the fibres to shrink back to their original size (or closer to it).

When cotton is mixed with other types of fabric, the potential for shrinkage is far less, but 100% cotton can be more susceptible to shrinkage. 

The hotter the water, the greater the likelihood that the cotton will shrink, so cooler washes are preferable wherever possible.

However, hot drying temperatures are more problematic than hot water. When you remove your cotton items from the washing machine, gently stretch them back into their correct size and shape. Laying them flat or hanging them is the best way to dry cotton items. 

Some cotton items are described as “pre-shrunk” by the manufacturer. This doesn’t mean they won’t shrink at all, but the amount of shrinkage should be less. You still need to follow the same guidelines when washing these items. 

 

Can I Tumble Dry Cotton?

The best way to dry cotton items is in the air, either by hanging it or laying it flat, but in most cases, it is possible to tumble dry cotton too. Before tumble drying, you should check the care instructions from the manufacturer to see if it is recommended. 

The heat from a tumble dryer has the potential to shrink 100% cotton more than a hot wash would, so it needs to be carefully managed. 

If you tumble dry cotton and it shrinks, it can be much more difficult to reverse the shrinkage because the heat resets the tension in the fibres.

For this reason, if you use a tumble dryer you should remove your cotton while it is still damp. 

This will enable you to reverse any shrinkage before it’s too late. Taking cotton out of the dryer before it is completely bone dry will also minimise creases and wrinkling.

 

How Can I Unshrink Cotton?

If your cotton has shrunk in the wash, it’s often possible to reverse the process and unshrink your clothes. If it has been tumble dried, reversing the shrinkage is much more difficult and may not always work. 

Here are the basic steps to follow to unshrink cotton:

1. Fill a basin with cool or lukewarm water and add either baby shampoo, a gentle detergent or hair conditioner. The latter works particularly well in relaxing the natural fibres of the cotton. 
2. Soak your cotton item for up to 30 minutes, gently agitating occasionally to ensure the fabric thoroughly absorbs the water. 
3. Remove after about 30 minutes and gently begin stretching the item back into its original shape. Don’t pull too much in one direction; work evenly around the garment, repeating if necessary. Let the cotton dry in the air.