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 just one day. Choose the temperature by what you are washing, and always check the care label in the garment first.
What the ten degrees do
The difference between 30 and 40 degrees sounds small, but it affects how clean the laundry gets. Forty degrees washes noticeably better and costs only a little more electricity. Thirty is enough for clothes worn for just one day. So the question is not which temperature is best, but which one suits what you are washing.
Enzymes and temperature
The enzymes in the detergent work best between 30 and 40 degrees. Enzymes are what break down stains in the detergent, and they need some warmth to work well. Below 30 degrees they become slow, and the result is often not quite as good as you had hoped, especially on sweaty clothes.
Grease, sweat and odour at 40 degrees
At 40 degrees grease and sweat dissolve faster, and odour is removed more reliably. The ten degrees therefore make a difference for exactly the things that are hardest to get out of clothes. That is why many people find clothes smell fresher after 40 degrees than after 30 degrees.
When 30 degrees is enough
For t-shirts and underwear worn for one day without heavy sweating, 30 degrees is enough. The same goes for things that only need freshening up. There is not enough grease or sweat here for the enzymes to need their best temperature. See bamboo underwear for women if you want pieces for every day.
When you should go up to 40
For sportswear, socks, towels and anything that smells, you should go up to 40 degrees. There is more sweat and grease in the fabric, and that needs the enzymes to have the best conditions. See bamboo socks for women and bamboo towels for the items that most often need a slightly warmer wash.
Odour and fibres
At 30 degrees the odour often stays in the fibres. This is especially true if the clothes were worn for exercise or lay damp in a basket. If you wash warmer, you get the odour out, instead of it coming back every time the fabric gets warm or damp again.
What the ten degrees cost
The ten degrees cost only a few øre per wash. The difference is smaller than most people think. So it is rarely a good reason to choose 30 degrees when the clothes really need a proper wash. Choose the temperature by how dirty the laundry is, and not by a few øre you might save.
Shrinking and the care label
Do clothes shrink more at 40 degrees? Only marginally. Shrinking mostly happens in the first wash, whatever the temperature. Always follow the care label if it says 30 as the maximum, and do not wash warmer than the instructions allow. The label is made for the individual garment and is the safest guide when in doubt.
How to choose in daily life
Split the laundry into two piles. One holds clothes worn for a day without sweat, washed at 30 degrees, and the other holds sportswear, socks, towels and anything with odour, washed at 40 degrees. If you can only make one pile, choose 40 degrees unless the label says otherwise.
Frequently asked questions
Do clothes shrink more at 40 degrees
Only marginally. Shrinking mostly happens in the first wash, whatever the temperature, so the difference between 30 and 40 degrees is small. Always follow the care label on the individual garment.
What do the ten degrees cost
A few øre per wash. The difference is smaller than most people think, so it is rarely a good reason to choose 30 degrees when the clothes are properly dirty.
Can you wash everything at 40 degrees
Almost. Always follow the label if it says 30 as the maximum, and do not wash warmer than stated. That way colours and shape last best, and you avoid damaging a garment.
You can find the full range at Bamboo-Clothing.com.
