The starting point in the care of 100% Merino wool, silk wool and 100% silk garments is to understand that they do not need such frequent washing as cotton clothing. They do not become dirty as easily as some other materials; in fact they repel dirt. Wool and silk like to be aired. They share the unique quality of renewal, they are capable of cleaning themselves with oxygen.
When you have two sets of woolen or silk underwear in a daily wearing and airing routine, they stay hygienic and fit for use for several days, often even for 2 to 3 weeks without washing. The woolens are dirt-repellent and do not offer any culture medium for bacteria or spores.
It is important that you use a biological washing agent which enhances dirt removal. Chemical detergents are harmful to wool and silk. In wool, they cause intertwining of fibers and felting. Silk does not felt, but the fiber does become hard.
It is recommended to wash woolen and silk garments by hand. Squeeze the garment lightly but avoid rubbing, rinse 2 to 3 times. If you use soap, it is advisable to add a drop of vinegar to the rinsing water to neutralise any lime remaining from the soap. Carefully squeeze the water out of the garment but avoid wringing, stretch the garment into its appropriate measurements lengthways. Spread it to dry but not in direct sunlight or close to an oven or other source of heat.