Forty degrees versus thirty degrees

Short answer: Forty degrees washes noticeably better and costs only a little more electricity. Thirty is enough for clothes worn for a single day.

What the ten degrees do

The enzymes in detergent work best between 30 and 40 degrees. At 40, grease and sweat dissolve faster and smells are removed more reliably. Below 30 the enzymes start to slow down.

When 30 is enough

For t-shirts and underwear worn for one day without heavy sweating. For anything that just needs freshening. See bamboo underwear for women.

When you should go up to 40

For activewear, socks, towels and anything with a smell. At 30 degrees the smell often stays in the fibres. See bamboo socks for women and bamboo towels.

Frequently asked questions

Do clothes shrink more at 40

Marginally. Shrinkage happens mostly in the first wash whatever the temperature.

What do the ten degrees cost

A few pennies per wash. The difference is smaller than most people think.

Can you wash everything at 40

Almost. Always follow the label if it states 30 as the maximum.