Many people have a wool sweater, cap or hat in the closet that they love, but don't wear any longer because it has become itchy or uncomfortable. Wool can take on a stiff or scratchy texture after years of use and washings. There are several new and tried-and-true items on the market that are designed for softening wool, but you can also do the same by soaking the item in a light solution of regular formulated hair conditioner and water.
Wash the wool item first in lukewarm water and shampoo to remove any dirt or dust. Shampoo is specially formulated for protein-based fibres, such as human hair and wool, and is much gentler than laundry soaps. Wash the item by submerging it and swishing it around. Do not wring or rub the surface or it may felt.
Rinse the wool item in clear, lukewarm water of the same temperature. Temperature variation may cause wool garments like hats to felt. You can add 1 tbsp vinegar to the rinse water help remove any residue (optional).
Fill up a new basin of clear lukewarm water and add 1 tbsp of conditioner. Stir the water around to make sure the conditioner is well mixed into the water.
Add the wool to the solution and gently submerge the item, stirring it around with your hand for 2 minutes as it absorbs the solution. If the wool item is a shaped hat or a fine weave, don't rub or agitate it roughly, as doing so may damage the texture. Remove the wool item.
Fill the sink with lukewarm water again (same temperature as before). Rinse the item gently, using the same dunking and swishing process. Remove the wool item.
Dry the item by rolling it gently in a dry towel, pressing it with your fingers to remove excess water. Repeat this process, using a new towel if necessary, until you have removed as much water as possible. Do not wring the item with your hands or the material may stretch.
Remove it from the towel. If the item is a hat, shape it gently with your hands, then lay the garment on a fresh dry towel and let it dry.
Use a conditioner that leaves your own hair soft and comfortable, not sticky. Try these steps out on a test piece of wool material if you are unsure. If the conditioner leaves a film on the swatch, then you are probably using a conditioner that is specially formulated. Switch to a regular conditioner. These softening steps can be used with wool yarn as well.
Don't use a conditioner that is formulated for special hair conditions. Don't rub the wool or wring it. Don't vary the water temperatures. Radical changes can damage the texture of some woven items.