Wool is naturally soil-repellent and in many cases does not need to be washed nearly as often as you might think. You can use the garment several times before it is washed; just air out the garment and let it rest for a time between uses. It gives the wool fibers time to recover their natural strength and elasticity.

Washing instructions:  Once you need to wash your wool-containing base layer, follow washing instructions for the base layer (above) but use detergent designated for wool material (preferably liquid); they have pH and active ingredients suited to wool.