From time to time you need to wash merino wool, and the most common mistake many people make, in addition to washing too often, is to use the wrong detergent. We recommend Toko Wool Wash 250ml.
Since merino wool does not allow bacteria that emit bad odors to stick, merino clothes do not start to smell as easily during activities with a lot of sweat, as clothes made of synthetic materials. So you do not have to wash the Merino garment as often as other clothes. Most of the time it is enough to just air them. Hang the garment outside the tent or on the backpack when you walk, and in a short time the garment smells almost like new.
Our colleagues at Lundhags have written a nice article about it: Merino wool care