Caring for a Felt Hat: Washing, Drying, and Storing

Why felt needs special handling

A felt sauna hat is made from pressed wool fibers that are matted together. This structure traps air and insulates your head and ears from the intense heat of a traditional sauna, which typically runs between 150 and 195 degrees Fahrenheit. The same qualities that make felt a great insulator also make it easy to damage if you wash it like ordinary clothing.

Wool felt shrinks, stiffens, and loses its shape when exposed to hot water, rough agitation, or strong detergents. Once felt shrinks, it cannot be stretched back. The goal of cleaning is to remove sweat and oils while disturbing the fibers as little as possible.

The good news: a felt hat does not need frequent washing. Most of the time, brushing and airing it out is enough. If you use a hat liner or bandana underneath, the hat itself stays cleaner and you can wash the liner instead.

For more on why people wear hats in the heat and what they are designed for, see sauna hat purpose.

Daily and weekly care between washes

After each sauna session, let the hat cool to room temperature, then shake it gently to remove loose dust and fibers. Hang it or lay it flat in a dry place with some airflow. This lets moisture evaporate before the next use, which reduces odor and slows the buildup of sweat salts.

Once a week, brush the hat with a soft-bristle brush, working in one direction from the crown down to the brim. This lifts dust and keeps the felt surface smooth. A lint roller also works for picking up small particles without pressing too hard.

If you notice sweat stains or salt marks, dab them with a barely damp cloth and let the area dry completely before wearing the hat again. Do not rub hard: rubbing can create shiny areas or mat the fibers unevenly.

For a related guide on what to wear on your head in heat, see hair protection in heat.

Spot cleaning stains and marks

For localized spots, mix a small amount of mild soap with lukewarm water. Dip a clean cloth into the solution, wring it out so it is only slightly damp, and blot the stained area gently. Work from the outside of the stain toward the center so it does not spread.

Rinse the cloth in plain water, blot again to remove any soap residue, then pat the area with a dry towel. Let the hat air-dry completely before storing it. Never use bleach, fabric softener, or a washing machine for spot cleaning.

If the hat has a stubborn smell that does not go away with airing, sprinkle a light layer of baking soda on the inside, let it sit for a few hours, then brush it out. This absorbs odors without wetting the fibers.

For context on what types of hats are suited for different sauna types, including infrared cabins, see hat for infrared cabin.

Hand washing when the hat needs a deeper clean

Sometimes a hat needs more than spot cleaning, especially after many sessions in a hot and humid room. Hand washing is the safest method, but it must be done gently.

Fill a basin with lukewarm water, never hot, and add a small amount of mild soap or wool shampoo. Submerge the hat and press it down with your hands. Do not scrub, twist, or wring the felt. Let it soak for a few minutes, then press and squeeze gently to work the soap through.

Drain the basin and refill it with clean lukewarm water. Rinse by pressing the hat under the water and squeezing it out softly. Repeat until the water runs clear. Lift the hat out with both hands so it does not stretch from its own weight.

To remove excess water, lay the hat on a thick towel, roll the towel up with the hat inside, and press down along the roll. This pulls water out without distorting the shape.

For an overview of how heat affects different kinds of hats, see what to wear in traditional sauna.

Drying without losing the shape

The most common way to ruin a felt hat is drying it too fast or with too much heat. A dryer, radiator, hairdryer, or direct sunlight will shrink, warp, and stiffen the felt. Always dry a felt hat at room temperature.

Place the hat on a form that matches its shape, such as a hat block or a clean, upside-down bowl covered with a towel. This prevents the crown from collapsing and the brim from flattening while it dries.

If you do not have a form, stuff the crown gently with a dry towel to help it hold its dome shape, and set the hat on a flat, absorbent surface. Turn it every few hours so it dries evenly on all sides.

Drying can take one to two days in a normal room. Wait until the hat is completely dry before wearing or storing it. Putting away a damp hat promotes mildew and can leave a musty smell.

For more on the role of hats in the sauna experience, see sauna hat purpose and felt hat vs cotton cap.

Storing the hat for the long term

Store a felt hat in a dry, well-ventilated spot away from direct sunlight and heat sources. Prolonged light can fade the color, and heat can dry out the fibers and make them brittle.

Keep the hat on a form or a hat stand when possible, so the brim and crown keep their shape. If you must stack it, place it on a shelf where nothing presses down on the crown.

A cotton or muslin bag offers good protection from dust while still letting air circulate. Avoid plastic bags, which trap moisture and encourage mildew.

If the hat gets wet from rain or heavy steam, do not store it until it is fully dry. Give it the same treatment as after hand washing: blot, shape, and air-dry at room temperature.

For guidance on choosing a hat that fits your sauna setup, see best indoor sauna gear and best infrared sauna gear.

Signs it is time to replace the hat

Even with careful maintenance, felt hats wear out. If the hat has lost its dome shape and no longer sits snugly on your head, if the brim has become permanently wavy, or if the felt feels hard and scratchy, it has likely reached the end of its useful life.

A hat that has shrunk noticeably from a hot wash will not stretch back and should be replaced. Similarly, if you see mold growing on the inside, discard the hat and start fresh, because the spores are hard to remove fully from felt.

Replacing a felt hat is not a large investment compared to the protection it provides. A well-cared-for hat can last for many years, but knowing when to retire it keeps your sauna experience comfortable and safe.

To see how a felt hat fits into the broader sauna wardrobe, review best traditional sauna gear and best portable saunas.

What to pick for your use

Questions

Can I put a felt sauna hat in the washing machine?

No. Machine washing agitates the wool fibers, which causes shrinking, felting unevenly, and losing the hat's shape. Always wash by hand with lukewarm water and mild soap.

How often should I wash my felt hat?

You rarely need a full wash. Brush it weekly and spot clean as needed. A full hand wash is only necessary a few times a year, or after the hat has been heavily soaked in sweat.

My hat got soaked in the sauna. What should I do?

Blot the hat with a towel to remove excess moisture, shape it on a form or stuffed towel, and let it air-dry completely at room temperature. Never use a dryer or radiator.

Can I dry my felt hat in the sun?

Direct sunlight can fade the color and make the wool fibers brittle. Dry the hat indoors away from windows and heat sources for the best result.

How do I remove odors from my felt hat?

Sprinkle a light layer of baking soda on the inside, let it sit for a few hours, then brush it out. Airing the hat between uses also prevents odors from building up.