Washing temperatures are a bit of a minefield. There are so many mixed messages out there, but it depends on a number of things. Here is our rough guide:
First, always check the garment label - this will give you the maximum temperature you can wash it at. Never go above that.
Just because an item of clothing can be washed at high temperatures, it doesn't mean it should. Washing at 30℃ saves around 40% in energy than higher temperatures - it's also better for the fabrics.
Towels can get very dirty very quickly and harbour lots of germs. Best to put these on a warmer wash, 40℃ will do it. If they're heavily soiled and starting to smell a bit funky, wash at 60℃ - that will help remove most of the germs causing the smells. Another way to eliminate germs is to hang your washing outside on a sunny day - the UV rays will take care of any germs clinging on.
It's not as straight forward as always washing your whites on a hot wash. It's better to pay attention to the type of fabric and the care guide on the garment. You might be surprised at how well a long wash at 30℃/40℃ actually works. If your washing is heavily soiled, you might be able to try soaking it first.
Denim doesn't like to be washed. The rule of thumb here is only wash them when they really need a wash. Then either gently hand wash them (don't rub to vigorously) or put them on a 30℃ or cold quick wash. If your washing machine has a delicates setting - use that.
Bright and dark colours
Hot washes can make colours bleed more easily. So keep the temperatures low, especially on the first wash. If your darks washing is heavily soiled, make sure you leave it on a full, long wash - that will give our laundry liquid longer to work it's magic.
Keep your woollens away from heat (They don't actually shrink, they felt - which isn't much better.) Wash them on a cold and delicate wash, shorter the better. Make sure you don't use a detergent with bio/enzymes, they damage wool. You can use Wilton Laundry liquid, it's enzyme free and our fabric softener will help keep the fibres moisturised. It's also best to dry wool laid out flat - it will help preserve it's shape.