Whether your beanie is made of cotton, wool or synthetic yarn, hand-washing is the way to get it clean. While it is possible to wash synthetic-fiber beanies in the washing machine, hand-washing ensures minimal wear and helps prevent the pilling that can result from friction with other clothing. Drying the beanie on a wig form ensures that it will keep its shape. After knitting or crocheting a beanie, hand-wash it before blocking to relax the fibers. Blocking is the process of getting a knitted or crocheted object wet, pinning it into place and letting it dry flat.
Fill a sink with just enough cold water to cover the beanie. If washing particularly dirty synthetic or cotton beanies, use hot water.
Add 1 to 2 teaspoons of laundry detergent formulated for knits and delicates. Choose a low-sudsing formula, such as one made for high-efficiency washing machines.
Swish the beanie through the water and gently squeeze it a few times to work in the detergent. Allow the beanie to soak for one hour.
Drain the sink and rinse the beanie with cold water. Squeeze out excess water by pressing the beanie against the bottom of the sink. Do not wring or twist.
Roll the beanie in a bath towel like a jelly roll. Press the towel to squeeze out most of the water.
Place the beanie on a wig form. If the edge has a picot or ruffle, pin it into the wig head with straight pins to help it dry flat.
Leave the beanie in a warm, sunny area or set it in front of a fan to dry.
Look for no-rinse detergent in yarn stores. This detergent is ideal for wool or other animal-fiber items, which can be difficult to rinse if there are too many suds, and will not leave buildup.
Never put wool or other animal-fiber beanies in the washing machine, as hot water and friction cause them to shrink.