Wool can easily lose its shape and become less defined if washed without care. Worst of all, it can shrink on you, becoming quite a few sizes smaller. Therefore always handle your woolen garments with extra care and make sure your woolen item really needs to be washed. Unlike cotton and man-made materials, wool does not need to be washed frequently. Just air your wool garment in-between wears.
Wash: Most wool garments can be washed in a washing machine on the special wool program. However hand washing your garment will always be preferable because it is more gentle. Use a detergent specially made for washing wool (like woolite) to make sure your woolen garment stays nice and soft. Dissolve the detergent in the water first, to prevent agitating the wet wool. Basically heat, agitation, and detergent are the enemies of wool, so aim to soak and rinse the dirt out. Just gently push your woolen garment under water and softly squeeze the suds through the clothing. Rinse thoroughly with cool or cold water.
Dry: Remove excess water with a towel by laying the item on a towel and rolling it up jelly-roll style, squeezing and pressing gently. Unroll then and leave in fresh air to dry. Never hang your wool garment out to dry as the wet fabric will stretch and loose shape. Instead dry your woolen garments flat in desired shape.