Can you wash and dry a hat?
Don't put caps into the laundry — either the washer or dryer. A high-efficiency washer that doesn't have a center agitating column can be okay, but even then it has to be cool water on the gentlest cycle, and you also have to be concerned about other clothes in the load squishing the hat's form.
Air Dry the Hat
As tempting as it might be to just throw your hat in the dryer, resist the urge. Even drying your hat in low heat can ruin its shape and cause shrinkage. Place your hat indoors on a towel and allow to air dry. To make sure your hat retains its shape, you can put a balled-up towel inside.
The tumbling motion of a washer or dryer will not only ruin the shape of the hat, it can also damage the lid of the hat as well. Even if you put it on the most gentle cycle the shape will most likely be ruined.
Gently squeeze excess water out of the hat, but avoid twisting the brim, which can bend it out of shape. Use a clean towel to pat down the hat. Either hang up the hat or reshape the hat and set it on a towel to dry.
You'll definitely want to skip the dryer, as the high heat and tumbling can damage your hat. Instead, after the wash cycle is done, dry your cap on a hat form or a round container (like an upside-down small bowl) to help keep the hat structure intact.
Fill a basin or sink with soapy water, using either detergent or dish soap. Hand-wash the hat by soaking the whole thing in the basin for around 10 minutes and then swishing it around a bit. If your hat is particularly gnarly, you may need to replace the water (not that I would know from experience).
— Let the hat air dry in a cool, well-ventilated area away from direct sunlight. TIP: Ensure the cloth is just damp and not soaking wet as this could cause water damage to the material.
Air Dry. The best approach to drying a baseball cap is to let the hat air dry naturally. Do this by setting the cap on a clean surface in a cool, dry area away from direct sunlight, which could cause fading and discoloration.
What's the Best Way to Dry My Hat? It's important when drying the hat to never put it in the dryer! Placing your hat in the dryer will cause it to shrink and lose its original form. It's best to let your cap air dry.
While not recommended if you are concerned about unwanted stretching, blow drying the hat can save you time. Just remember to dry it on the low-heat or cold-air setting so that the hat's structure and size isn't compromised.