To clean a cashmere sweater, the washing machine should be set to the most delicate cycle available. On most machines, the cycle will be labeled "delicate.. Machines with a large number of cycles may offer choices such as silk, wool or lingerie. The delicate cycle will help prevent any stretching or excess wear on the cashmere sweater while it is being cleaned. If the machine offers a choice of spin cycle length, choose the shortest spin cycle available to minimize wear on the sweater.

Hot water will shrink and damage cashmere. Choose cold water for washing a cashmere sweater in a washing machine. Verify that the machine is set to use cold water both for the wash and rinse cycle so that the sweater is not subjected to hot water at any point while it is being cleaned. While tempting to use warm water if the sweater is especially soiled, even warm water can damage and shrink cashmere fibers. At no time should the water temperature be higher than 86 degrees Fahrenheit.

Use a detergent made specifically for delicate fabrics. Detergents designed specifically for cashmere are available. While such a detergent works well, it is not absolutely necessary. Any type of soap made for delicate clothing is suitable for use with cashmere. Those designed for hand-washing delicate fabrics are also suitable. In a pinch, baby shampoo can be used to clean a cashmere sweater.

Protect cashmere sweaters in the washing machine by placing them in a lingerie or laundry bag. If a laundry or lingerie bag is not available, use a pillowcase that is tied shut at the top. A white pillowcase will ensure that no color from the case bleeds onto the sweater. Place only one sweater in each bag. For even more protection, add some towels to the washer to help cushion the sweaters as they spin and tumble in the washer. Avoid adding any items that could damage a cashmere sweater, such as jeans with buttons and grommets, shirts with buckles or other ornaments and items like pantyhose or tights that could wrap tightly around the sweater.