Wool blankets are great in the winter. They are warm, cuddly, fairly lightweight and can become family heirlooms if cared for properly. Cleaning a wool blanket can require a bit more effort than something made of cotton, but isn't overly difficult.
Check the tag of blanket if it has one)to see if it has washing instructions, and, if so, follow them. The manufacturer usually knows best. If it recommends dry cleaning, this is probably the best way to go, though it may be costly.
If the tag indicates the blanket is machine-safe, use a special wool-cleaning product. Regular detergent could damage and destroy the fibres.
Place the blanket in the washing machine along with the soap and set the machine to the gentle cycle with cold water, so as to avoid putting the blanket through a rough washing at high temperatures.
After a minute in the spin cycle to remove excess water, remove the blanket from the washing machine. A full cycle could be too strenuous on the wool fibres and could stretch them.
Air dry the blanket on a clothesline or rack. Never place it in the dryer, which could shrink the blanket, ruining it.