The Best Way to Wash a Baseball Cap

Woman in baseball cap exercising
Sam Edwards/Getty Images

Whether you wear a baseball cap for work or play, there may come a time that it needs a bit of cleaning. But before you start, take time to look at the little tag on the inside to get an idea of the fiber content of the hat and any manufacturer’s cleaning instructions. Of course, your tag may be long gone or unreadable; and caps made before 1983 didn’t even require a tag. So, read carefully for instructions on the safe cleaning of almost any type of baseball cap.

Cleaning Cotton or Man-Made Fiber New Baseball Caps

Recently manufactured baseball caps are often made of cotton twill, cotton polyester blends, or jersey mesh. These fabrics are strong and durable and usually colorfast. New caps use a plastic form to shape the brim, not cardboard. These plastic forms can withstand a wash without becoming deformed.

To clean, pretreat exceptionally dirty areas like sweatbands with a solvent-based spray or gel stain remover like Zout or Shout or Spray 'n Wash or a bit of heavy-duty laundry detergent like Persil or Tide. These two detergents have a high enough concentration of enzymes to break apart body soil and oil molecules. Work the stain remover into the soiled areas using a soft-bristled brush and allow it to work for at least 15 minutes before washing. This pretreatment is necessary to remove the body oils that come along with perspiration.

Wash the cap with a load of similarly colored clothing on the delicate cycle using cool water. Do not use chlorine bleach even on a white cap. If the cap looks dull and you wish to brighten the colors, mix a solution of oxygen-based bleach and warm water following package directions. Completely submerge the cap and allow it to soak for at least four hours or overnight. Rinse well and air dry.

If you are very concerned about protecting the shape of the cap, you can use a specially designed hat form and toss it in the washer. Allow the cap to dry in the form or over a large coffee can or another head-shaped container. Do not put baseball caps in the dryer because excessive heat and tumbling action can distort the hat's shape.

If the cap has a cardboard or paper-stiffened bill, you will have to do spot-cleaning only. Use a soft-bristled brush and scrub the stained areas with a heavy-duty detergent/water mixture. Do not over wet the area. Blot with a clean white cloth dipped in water. Allow to air dry. You may need to repeat the steps several times.

You have probably heard of washing caps in the dishwasher on the top rack. I would not recommend this because dishwasher detergents are quite harsh and often contain bleach that can ruin your cap. Excessively high temperatures are not good for the fabric and may cause shrinkage.

Cleaning New Wool Baseball Caps

Wool baseball caps should be hand washed using cool water and a mild detergent designated for wool. Be gentle and don’t scrub or twist the fibers. Rinse well in cool water and roll gently in a thick towel to absorb most of the moisture. Allow to air dry on a head-shaped object. If you dry your wool cap on your own head, it will dry to the precise shape of your head.

Cleaning Older or Commemorative Baseball Caps

Commemorative caps should always be stored in a covered case to prevent dust and grease from accumulating on the cap. These should only need a light dusting or brushing once a year to keep them at their best. Always store away from direct light and intense heat.

If a deeper cleaning is needed, first do a colorfastness test. Using a white cloth with a bit of mild detergent, gently rub an inconspicuous area of the cap. If there is color transfer, do not proceed. If the fabric is colorfast, continue using the cloth to clean the entire hat. Do not immerse the hat in water. The bill may be shaped using cardboard that will dissolve. Dip the cloth in clean water to “rinse” the cap by wiping away any cleaning solution. Air dry on a head-shaped form.

If you have an autograph that you want to preserve, keep the cap in a dark, air-conditioned space to prevent fading and mold or mildew from forming. If you want to wear the autographed cap, protect the signature by covering the signed area with a white, pressing cloth and iron the area on high heat. This will help set the ink.

wash baseball cap
Illustration: J. R. Bee © The Spruce, 2018 

Prefer a Different Type of Hat?

If a fabric or mesh baseball cap just isn't your style and you prefer a leather, fur, fedora, straw hat, or even just a knitted cap, learn how to care for each and every one.