How to Wash a Backpack Without Damaging It

Your pack smells like a gym bag after a summer of sweaty hikes, there’s a muddy streak down the back panel, and the washer is right there with the lid up. The care tag faded off years ago, and one guide says gentle cycle while the next says never.

That split isn’t your fault, and hesitating makes sense. Some of that advice is written for any bag at all, not for a hiking pack, and a good pack wasn’t cheap.

What you want is simple: a straight answer on the washer, and how to wash a backpack so it comes out clean, without the smell or the damage.

By the end you’ll know why a hiking pack stays out of the machine, how to wash and dry it by hand as the makers describe, and how to tell a pack that needs a wash from one no wash will save, so the one that fits you keeps going.

Can You Put a Backpack in the Washing Machine?

For a hiking pack, no. Osprey, Gregory, Deuter and Mystery Ranch all say not to machine wash their packs, and REI says never machine wash or tumble dry. Deuter explains that the agitation wears down the coating inside the fabric, and Osprey says the machine can harm the pack’s structure.

Most hiking pack fabric has a polyurethane (PU) coating on the inside, which is what stops rain soaking straight through. Deuter’s cleaning guide says the tumbling in a machine stresses that coating and the fabric, and that detergent left behind stays in the material.

Heat is the other problem. Gregory warns that a dryer can damage a pack’s protective coatings, so the dryer is off the table even if the wash seemed to go fine.

Then there’s what’s built into a hiking pack: foam in the shoulder straps and hip belt, and often a frame or a framesheet (a stiff sheet inside the back panel). Those parts give the pack its shape and its carry, and a machine tumbles them along with the coating.

You’ll find gentle-cycle instructions online, some of them from outdoor stores, but the pack makers I read all say no for their own packs. If a bag’s care label says it’s machine washable, that’s a different case, and you follow the label.

And yes, plenty of school bags go through the washer every term and come out fine. Some are labeled machine washable, and a simple school bag doesn’t carry the coating, foam harness and frame a hiking pack does, which are the parts its maker says the machine harms.

So when the tag is long gone, look at how the pack is built. I’d treat any pack with a frame, a padded foam harness and coated fabric as a hiking pack, and keep it out of the machine.

If you only need the method, the step-by-step hand wash is further down this page.

Which Clean Does Your Pack Need Today?

Usually your pack needs a wipe, not a wash. REI suggests a quick once-over after every hike or overnight and says you may go years between deep cleans. Deuter says to spot clean light dirt after a hike and save a full wash for when it’s very dirty or sweaty.

How dirty the pack actually is decides which clean it gets:

• A wipe-down after a hike, for dust, crumbs and the sweat on the straps, so the dirt never gets the chance to build up.
• A spot clean for a muddy streak down the back panel or a single stain, so you clean one patch instead of soaking the whole pack.
• A full hand wash when the pack is very dirty, or the straps smell after a summer of sweaty hikes, which is the case Deuter saves it for.

There’s no fixed number of washes a year to aim for. Wash when the pack needs it, and not before.

A full hand wash of a big pack takes a tub, some time and a long dry. The after-hike wipe is the habit I’d build first, because it’s what keeps that big wash rare.

The Quick Clean After a Hike

Empty every pocket and shake out the grit and crumbs. Then wipe the shoulder straps, back panel and hip belt with a damp cloth, since those are the parts that sit against your sweat all day. That’s REI’s quick once-over and Deuter’s spot clean in one.

Leave the pack to air out with the pockets open before it goes back in the closet. A pack shut away while it’s still a bit damp is one way a smell gets started, and the drying section below explains why.

Spot Cleaning Mud and Stains

For a muddy streak or a mark, REI suggests a little mild soap on a sponge, worked on just that spot. Go gently, because Gregory says heavy brushing can damage a pack’s coatings.

Blood is the one stain with its own method. Mystery Ranch suggests hydrogen peroxide for blood stains, and that’s the only use it names for it, so keep it to blood.

Keeping Zippers Clean So They Don’t Stick

Zippers need cleaning now and then, but not scrubbing. REI says not to scrub them, since many have a water-resistant coating. After heavy use, Mystery Ranch suggests blowing out the zipper chains and sliders with compressed air.

Save zipper lubricant for a zipper that’s actually stuck, and use one made for zippers, as REI suggests.

How to Wash a Backpack by Hand, Step by Step

Check your maker’s care instructions first, since makers differ on water temperature, soaking and what comes off. Then empty it, remove only what the manual allows, and wash it gently in lukewarm water with mild soap, not detergent. Rinse until no soap is left, and dry it in the shade.

1. Check Your Maker’s Care Page or the Label First

The makers agree on the big things, but they differ on water temperature, whether to soak the whole pack, and what comes off. Your manual settles those for your pack.

All five sources agree on no washing machine, mild soap and drying out of direct sun, and the ones that mention a dryer say no to it. This is where they differ:

If your manual is long gone, I’d stick to what they agree on: no machine, no dryer, mild soap and shade, and keep the scrubbing light, as Gregory and REI advise. Keep the water lukewarm, and leave on anything that doesn’t obviously come off.

2. Empty It, and Take Off Only What the Manual Says Comes Off

Osprey says to take off a removable harness and hipbelt and clean them separately. REI says to remove a metal frame only if the manual says it comes out.

Deuter goes further: its back systems aren’t designed to be removed, and taking out the frame or rods risks damaging the pack beyond repair. So if a part doesn’t come off easily, leave it where it is.

Take the rain cover off and spot clean it with a damp cloth instead of soaking it, because Deuter says the colors can bleed. Rinsing, drying and checking the cover is its own routine, covered in my guide on how to look after your rain cover.

Take out the hydration bladder too. It needs its own cleaning, separate from the pack.

3. Wash Gently with Mild Soap in Lukewarm Water

Use soap, not detergent: castile soap or a wash made for technical packs and clothing (REI), a pH-neutral soap (Deuter), and no detergents or solvents (Gregory). REI’s deep clean method starts with about 6 inches (15 cm) of lukewarm water.

Isn’t detergent just a stronger soap? For a pack, the trouble is what it leaves behind. Deuter says detergent residue stays in the fabric and can irritate sensitive skin where the shoulder straps sit.

Swish the pack around and work it with a sponge or a soft brush, keeping the scrubbing light, since Gregory says heavy brushing can damage coatings.

Before you put the whole pack under, check the manual. Some makers describe a tub or large sink, while Gregory’s European advice is to submerge only as much of the pack as you need to scrub.

For a really grimy pack, Mystery Ranch suggests Nikwax Tent & Gear SolarWash for its filthiest packs, and Nikwax lists it for backpacks. It’s for a pack plain soap can’t shift, not something you need to buy first.

I’ve hand-washed my own pack with Nikwax Tech Wash, though Nikwax lists that one for outdoor clothing, not packs. If you’re buying a cleaner for the pack itself, SolarWash is the one Nikwax names.

4. Rinse Until No Soap Is Left

REI’s method is to drain the soapy water, then add about 6 inches (15 cm) of cool water and rinse, twice if needed.

Take your time here, because Osprey also says to remove every trace of soap, and Deuter says residue left in the fabric, together with sweat and sun, wears the material faster.

5. Dry It in the Shade

Hang it out of the sun and away from heat until it’s dry all the way through. The next section covers how, and why it matters so much.

Most of the care is in step 1. The manual tells you what you can’t undo later, like pulling out a frame that was never meant to come out.

If it helps to see it done, this short video from REI (about a minute and a half) shows the same steps on a real pack, including where sweat and grime build up most: the back panel, shoulder straps and hip belt.

How to Dry Your Pack So the Smell Doesn’t Come Back

Air dry your pack out of direct sun and away from heat, as every care page I read advises. Towel off the water, open every zipper and hang it upside down. Never use a dryer or hair dryer, and let it dry all the way through before you store it.

You washed it, it felt dry, and a week later the closet smells like old socks. Nikwax says a pack’s inner coating breaks down if it’s left damp for long periods, and the outside of a pack can feel dry well before the foam and seams do.

Here’s how to dry it properly:

• Towel off the extra water first, so there’s less left to drip and evaporate out of the foam.
• Open every zipper and hang the pack upside down, as Deuter describes, so water runs out of the pockets instead of pooling at the bottom.
• Keep the zippered pockets open until it’s fully dry, which Gregory also advises, so air can reach the inside.
• Keep it out of direct sun and away from heat. Gregory’s care page rules out a dryer, a hair dryer or a heat gun, because heat can damage the protective coatings, and Deuter adds no ironing.

Wouldn’t the sun dry it faster? It might, but REI says UV light can degrade the fabric, and Mystery Ranch says never to dry a pack in direct sunlight.

Nikwax goes further and states that synthetic pack and tent fabrics can lose up to half their strength in two weeks of continuous sun. A slower dry in the shade spares the fabric that.

How long it takes depends on the pack and the room, so there’s no number to aim for. The test is the feel: the inside, the seams and the foam should all be fully dry before the pack goes away.

Once it’s dry, Deuter suggests a quick check: drop a few drops of water on the fabric. If they soak in instead of beading up, the pack may need reproofing.

Mystery Ranch names Nikwax Tent & Gear SolarProof for water repellency. Deuter warns that waterproofing agents can soak into the strap fabric and irritate skin, so keep any reproofer off the shoulder straps.

How to Get a Musty Smell or Mildew Out of a Backpack

Start with a hand wash and a full dry in the shade. A smell that returns can come from a pack stored before it was fully dry, or an inside coating turning soft or sticky. Gear Aid’s odor eliminator can help, though it isn’t promised to remove mildew.

You’ll see advice to put a mildewed pack out in the sun, or to wipe it down with rubbing alcohol or vinegar. None of the makers I read support those, and the sun one runs straight against their drying advice, which is shade every time.

The method that fits what the makers say is the one already above: a full hand wash with mild soap, a thorough rinse, and a complete dry in the shade.

It’s maddening to wash a pack properly and smell the same mustiness the moment it’s dry. For a smell that survives a proper wash, Gear Aid makes Revivex Odor Eliminator (formerly MiraZyme). It uses water-activated microbes to remove odors from sweat, mold and mildew.

Gear Aid’s directions for backpacks are to spray it on rather than soak the pack, leaving the fabric damp but not saturated, then skip the rinse and let it air dry out of the sun. Its instructions also say to test for colorfastness first.

Gear Aid is clear about the limit: it removes the odors, but it doesn’t guarantee to remove the mold or mildew itself.

A smell that returns as the pack dries can come from two places:

• A pack put away before it was fully dry, since Nikwax says the coating breaks down when it’s left damp for long periods.
• An inside coating that’s turning soft or sticky, which may mean the coating itself is breaking down. That’s the one a wash can’t fix.

I’d try the proper wash and a full dry before buying anything for the smell. An odor product treats the smell rather than the cause, so the drying habit does more for the pack than any bottle.

When Washing Won’t Save Your Pack

If the inside feels tacky or is flaking, or the smell returns every time it dries, the coating may be breaking down, which a wash won’t reverse. Before you replace the pack, check the maker’s repair or warranty terms. Mystery Ranch asks for a clean pack before it repairs one.

This is the hard part when the pack still fits you well. You found the one that sits right on your hips, and starting over is the last thing you want.

So judge it by two things: how the inside coating feels, and whether the smell keeps coming back after a proper wash and a full dry. If the coating feels normal and the smell goes, it was a washing problem.

If the coating is tacky or flaking and the smell comes back every time, I’d call that a pack past what washing can fix, and stop spending soap and weekends on it.

Before you give up on it, check what the maker offers for repairs or warranty. Mystery Ranch’s terms, when I read them, require a pack to be washed before it’s sent in, and a dirty pack may be charged a $25 equipment maintenance fee or sent back unrepaired.

If it is time for a new pack, the worry is buying one and getting the fit wrong again. My beginner guide walks through what size and features actually matter, so the next one is easier to get right.

For the pack you have now, the next step is small. Before the next wash, look up your pack maker’s care page, or find the label inside the pack, and check what comes off and how warm the water should be.