That go-to hat picks up sweat, sunscreen, and hair oil every time you wear it, and after a season the sweatband greys out and the crown starts to smell. The good news is that most hats clean up right at the kitchen sink, as long as you match the method to the material.
The wrong move can ruin one, though. Soak a straw hat or a vintage cardboard-brim cap and it warps for good, and run a wool cap through hot water and it shrinks a size. Here is how to clean every kind of hat at home, from a cotton baseball cap to a felt fedora, without wrecking the shape or fading the color.
Key Takeaways
- Check the brim first: a cap made before 1983 often has a cardboard brim that water turns to mush, so spot-clean vintage caps only.
- Hand washing is safest: for modern baseball caps and knit beanies, a cool soak with mild detergent beats the machine or dishwasher. Cap maker New Era recommends spot-cleaning only.
- Never use heat: skip the dryer and air dry the hat on a rounded form (an upturned bowl, a coffee can, or a ball) so it keeps its shape.
- Match the method to the material: wool shrinks in hot water, straw and cardboard warp when soaked, and suede and felt clean dry with a brush.
How Often Should You Wash Your Hat?
Give most hats a deep clean two or three times a season. If you wear the same cap every day for workouts or outdoor work, though, wash or sanitize it weekly, since that is where sweat and bacteria build up fastest.
Let your eyes and nose decide the rest. White salt lines on the band (dried sweat), grime along the brim, or dust settled into the weave all mean it is time. And if the sniff test makes you recoil, that hat is overdue for soap and water.
How to Clean a Baseball Cap
This method works best for modern baseball caps (acrylic, wool blends, or cotton) with plastic brims.
Important Warning: If you have a vintage cap made before 1983, tap the brim. If it sounds hollow or cardboard-like, do not submerge it. Water turns that old paperboard to mush and the shape is gone for good. Stick to spot cleaning for those vintage finds.
Worth knowing before you soak: New Era, which makes MLB on-field caps, recommends spot-cleaning its caps with cold water and a soft brush rather than fully submerging them. For an everyday cotton or poly cap, the sink soak below works fine. For a fitted cap with a stitched logo or patch you want to protect, use the spot-clean method further down instead.
- Time: 30 minutes (plus air drying)
- Difficulty: Beginner
What You’ll Need
- Toothbrush or small nail brush
- Mild dish soap or laundry detergent
- Small bowl
- Clean sink or bucket
- Ball cap buddy, melon, coffee canister, or rolled-up towel
1. Rinse the Cap
Give the hat a quick rinse under cool running water. This knocks loose the surface dust and loose dirt before you start scrubbing, so you are not just grinding grit into the weave.
2. Spot Clean Problem Areas
Pour a little dish soap into a small bowl with water and mix it up. Dip your toothbrush into the suds and gently scrub the dirtiest spots. Pay special attention to the inner sweatband and the seam where the brim meets the crown, since that is where oils and salt collect. Use small circular motions to lift the grime.
3. Soak the Hat
Fill your sink or a bucket with cool water. Add a squirt of detergent and swish it to raise some suds, then submerge the hat fully.
Let it soak about 10 to 15 minutes. Every few minutes, give it a gentle swirl with your hands. If the water turns brown or grey, drain it and soak again in fresh soapy water.
4. Rinse Thoroughly
Drain the soapy water and rinse the cap under cool running water. Keep rinsing until the water runs clear and no suds are left. Be gentle here: do not wring, twist, or crush the brim, which can crack the plastic insert.
5. Air Dry Correctly
Pat the hat with a towel to blot the dripping water. To prevent shrinkage or warping, set the wet hat on a ball cap buddy, an overturned bowl, a coffee can, or even a small melon. It dries in the right shape that way. Keep it out of direct sunlight so the color does not fade.
How to Clean Different Hat Materials
Not every hat handles water the same way. Different fabrics react differently to soaking and scrubbing, so follow these material-specific rules before you reach for the sink.
Wool Hats
Wool loves to shrink, so keep it cool. Fill your sink with cool water (never hot) and a wool-safe detergent or mild soap.
Gently massage the hat in the water, then let it soak about 20 minutes. Rinse with cool water. Instead of wringing it out, roll the hat in a thick towel and press to absorb the moisture. Reshape it carefully and let it air dry flat, away from direct heat.
Fedora Hats
Fedoras usually want dry methods. Grab a soft-bristled clothes brush and brush the hat gently to lift dust and debris, always working in the direction of the nap (usually counter-clockwise).
For a greasy spot, sprinkle a little baking soda or baby powder right on it, leave it about 15 minutes, then brush the residue away. The powder pulls the oil out of the felt. If the leather sweatband inside looks grimy, clean it with a leather conditioner or Fiebing’s Saddle Soap, which cleans the band and keeps the leather from cracking.
Straw Hats
Water is the enemy of straw. Soak a straw hat and the fibers swell and the shape distorts. Instead, wipe it down with a barely damp cloth to lift surface dust.
For a stain, use a dedicated straw hat cleaner or a very small amount of Windex on a cloth and gently blot it. If the hat does get wet, dry it right away with a towel and reshape the brim. To fix a wonky brim, use steam: boil a kettle or run a garment steamer over the straw, then mold it back into place with your fingers.
Suede Hats
Suede is porous and stains easily. Use a stiff-bristled suede brush to knock off dirt and lift the nap (the fuzzy texture) back up.
For matted areas or scuffs, buff them out gently with a suede eraser or a bit of fine-grit sandpaper. For oil or sweat marks, sprinkle cornstarch to absorb the oil, or try a very dilute mix of baby shampoo and water (1 part soap to 15 parts water). Test a hidden spot first either way.
Felt Hats
Treat felt much like wool. Brush the hat from the top down with a soft-bristled brush to pull out the dust that settles deep in the fibers.
If it is misshapen, hold it over steam from a kettle or steamer and gently mold it back by hand. Let it dry fully on a hat form or a safe rounded surface before you wear it again.
Leather Hats
Leather needs a little moisture to stay healthy. Wipe off surface dirt with a damp cloth. For a deeper clean, use a dedicated leather cleaner like the Lexol Leather Care Kit. Avoid soaking the leather, and follow up with a conditioner to keep it supple and water-resistant.
How to Spot Clean a Hat
If you only have a small smudge, or you are dealing with a vintage hat with a cardboard brim, spot cleaning is your safest bet. It puts almost no water into the fabric, so nothing warps.
- Time: 15 minutes
- Difficulty: Beginner
What You’ll Need
- Clean washcloth (white is best to avoid color transfer)
- Soft toothbrush
- Mild detergent or diluted shampoo
1. Prepare the Solution
Mix a teaspoon of mild detergent into a cup of cool water. You want it lightly bubbly, not a foamy bubble bath.
2. Dab and Scrub
Dip your washcloth in the solution and wring it out so it is damp, not dripping. Dab the stain firmly. For tougher grime like dried mud, switch to the toothbrush and scrub in small circles.
3. Rinse and Dry
Dip a clean section of the cloth in plain water and wipe away the soap residue. Let the hat air dry indoors, away from direct heat or sunlight, which can fade the colors.
How to Get Rid of Sweat Stains
Those yellow marks are more than dirt. Sweat carries salt, minerals, and body oil (sebum), and once it dries into the band and oxidizes, especially after time in the sun, it yellows and sets. That is why an old stain needs a real treatment instead of a quick wipe.
One rule first: keep chlorine bleach away from yellow sweat stains. It reacts with the protein residue in dried sweat and can turn the yellowing darker instead of lifting it. Reach for oxygen bleach or white vinegar instead, both of which break the buildup down without setting the stain.
Since shampoo is built to break down body oils, it is a good first weapon. Dab shampoo directly onto the sweat line, scrub with a toothbrush, and let it sit 15 minutes before rinsing.
For tougher white stains on light-colored hats, use OxiClean, an oxygen bleach. Dissolve a small amount in warm water, apply it to the stain, and let it work about 10 minutes. Note: always test colorfastness on the inside of the brim first so the oxygen bleach does not lighten your hat.
You can also make a paste of baking soda and water, scrub it into the band, let it sit an hour, then spray it with distilled white vinegar. It fizzes and helps lift the grime. Rinse thoroughly with cool water afterward. On a dyed or embellished hat, test a hidden spot first, since vinegar’s acid can fade some colors.
Can You Wash Hats In the Washing Machine or Dishwasher?
The short answer: yes, but both carry real risk, so save them for sturdy, unstructured caps.
The Washing Machine Method:
You can wash unstructured baseball caps or bucket hats (cotton or canvas) in the washer. Always use a mesh laundry bag to keep the straps from tangling.
- Use the gentle or delicate cycle with cool water.
- Use mild detergent (no bleach).
- Never put the hat in the dryer. Air dry only.
The Dishwasher Method:
This is a popular hack, but go in with your eyes open. Dishwasher detergents are often harsh and contain bleaching agents that can strip hat colors, and the heat can warp plastic brims.
- Place the hat on the top rack only, and use a plastic hat frame to hold the shape.
- Use a detergent that is free of bleach and citric acid; skip lemon-scented pods.
- Turn off the Heated Dry cycle. This is the critical step. That heat will shrink cotton, warp the plastic brim, and can even melt the glue holding the cap panels together.
