How to Clean a Mattress: The Deep Clean, Stain by Stain

To clean a mattress, strip the bed and wash the bedding hot, vacuum the top, sides and seams, spot-treat stains by blotting with an enzyme cleaner or a little dish soap and cold water, let it dry, cover it with baking soda for several hours, vacuum again and put a waterproof protector on before the sheets go back. That’s the whole job. Everything else on this page is about doing it without wrecking the foam, choosing the right fix for each stain, and knowing when cleaning isn’t the answer.

The single most important rule is use as little liquid as possible. Mattresses are thick blocks of foam, fibre and fabric that dry slowly from the inside, and moisture trapped deep in the layers is how a simple coffee spill becomes a mildew problem. The Sleep Foundation’s guide is blunt that memory foam “is not designed to get wet,” and DreamCloud warns that “harsh cleaners, steam, and soaking-wet cloths” are harder on a mattress than most stains. Put the cleaner on the cloth, not the bed.

The second rule is about money. Every partner-brand warranty we read — Saatva, Nectar, DreamCloud and Puffy — excludes stained mattresses, and Nectar and DreamCloud void their warranties if you remove the cover. So the cheapest cleaning product you will ever buy is a mattress protector, and the worst cleaning idea is unzipping the cover and putting it through the washing machine.

A word on how we wrote this. We don’t run a cleaning lab and we haven’t tested these methods on our own mattresses. This guide pulls together the published care instructions from the Sleep Foundation and the brands we cover, public-health guidance from the EPA, CDC and the Asthma and Allergy Foundation of America (AAFA), and the brands’ own warranty terms. Where the evidence is thin — and for baking soda it is — we say so.

The Sleep Foundation, Nectar and DreamCloud publish slightly different versions of the same routine. Here is the combined method, in the order that avoids the classic mistake of putting baking soda on a damp mattress and ending up with paste.

What you need. A vacuum with an upholstery tool and a crevice tool (a HEPA filter is better if anyone in the house has allergies), a box of baking soda, a few clean white cloths so dye doesn’t transfer, a spray bottle, cold water, mild dish soap or a commercial enzyme cleaner, and optionally white vinegar and 3% hydrogen peroxide. A fan helps with drying. Pick a dry, warm day if you can and start in the morning, because the mattress needs to be bare for most of the day.

Step 1: strip and wash. Take off sheets, pillowcases, any pad and the protector and wash them in the hottest water their labels allow. AAFA says water of at least 130°F kills dust mites, so if your bedding tolerates it, that is the setting to use. While they wash, you have the mattress to yourself.

Step 2: vacuum. Go over the whole top surface slowly with the upholstery attachment, then the sides, then run the crevice tool along every seam, piping edge and tuft. Seams are where skin flakes, dust and — if you have them — bed bugs collect. If your mattress is double-sided, do the underside too; most modern foam and hybrid beds are one-sided, so the bottom only needs a quick pass.

Step 3: spot-treat stains. This is where most damage happens. Dampen a cloth with your cleaner rather than spraying the mattress, blot from the outside of the stain toward the centre so it doesn’t spread, and never scrub — rubbing pushes the stain into the foam and frays the cover fabric. Then blot again with a cloth dampened in plain cold water to lift the cleaner out, and press with a dry towel. The stain chart below covers what to use for each type of mark.

Step 4: let it dry. Open a window or point a fan at any treated patch for an hour or two. DreamCloud advises allowing more drying time than seems necessary, since moisture can sit deep in the foam after the surface feels dry. Don’t use a hair dryer; DreamCloud says heat can damage foam layers and set whatever is left of the stain.

Step 5: baking soda. Sift or shake a thin, even layer over the whole sleeping surface. Sleep Foundation suggests leaving it “for at least a few hours,” or overnight for convenience; DreamCloud says overnight if possible. Longer doesn’t hurt. Nectar suggests opening a window to let sunlight in while you wait — a nice idea for airing the room, though we haven’t found evidence that window light reaching a mattress does much against mites or bacteria.

Step 6: vacuum it off. Use slow, overlapping passes and empty the canister afterwards. Fine baking soda can clog bagless vacuum filters, so check yours.

Step 7: protect it. Only once the mattress is completely dry, put on a waterproof protector, then the sheets. A protector over a damp bed traps moisture against the foam, which is the opposite of what you want. If you don’t own one, our best mattress protector guide picks the ones worth buying, and our topper vs pad vs protector explainer covers which layer does what.

Every mattress-cleaning guide on the internet tells you to use baking soda, including all three we based this method on. So it’s fair to ask what the evidence is. The honest answer: we couldn’t find a controlled study testing baking soda on mattresses. What exists is long-standing household practice and the brands’ own advice.

What baking soda plausibly does is two things. It’s a fine, dry powder that absorbs some surface moisture and the oils that come with it, which is why DreamCloud tells you to put it on oily stains before any water. And it’s mildly alkaline, so it can neutralise some acidic odour compounds — the sour notes of old sweat, for example. That makes it a reasonable deodoriser for a mattress that smells a bit stale.

What it doesn’t do is clean, disinfect, remove stains or kill dust mites. It sits on the surface; it doesn’t reach the inner layers where a deep urine or vomit smell lives; and it doesn’t break down the proteins in biological stains the way an enzyme cleaner does. If your mattress smells because something soaked into it, baking soda will mask the top layer of the smell for a while, not fix it.

Our verdict: use it — it’s cheap, it’s safe on every mattress type, and as a final step it does freshen a bed. Just don’t treat it as the cleaning. The vacuuming and the spot treatment are the cleaning. Skip the “add essential oils to your baking soda” trend if anyone in the house has asthma or allergies, and never mix baking soda and vinegar together on the mattress: the fizz is satisfying, but the two neutralise each other and leave you with damp salty water in the foam.

The right product depends on what the stain is made of. Biological stains — sweat, blood, urine, vomit — are protein-based, and the Sleep Foundation says “the best option is typically a commercial enzyme cleaner” for them, because the enzymes break the proteins down rather than just diluting them. Food and drink stains respond to cold water and dish soap. Oily stains need to be absorbed before they are washed.

Sweat and yellow stains. The yellow patches on an older mattress are mostly sweat and body oils that built up over years, which is why they’re so common under the pillow and hip zones. Treat them like any biological stain with an enzyme cleaner or dish-soap suds on a cloth. For stubborn yellowing, Nectar suggests you “lightly spray the area with 3% hydrogen peroxide, just don’t dampen it.” Be realistic: years of yellowing rarely comes out completely. If you sleep hot and sweat a lot, a protector is what stops this happening to the next mattress.

Blood. Cold water only — heat cooks the proteins into the fibres. Blot as much as you can, then use an enzyme cleaner. Sleep Foundation suggests a 1:1 mix of cold water and hydrogen peroxide as an option for tougher stains; DreamCloud warns peroxide may bleach fabric at full strength or if left too long, so test it on a hidden corner first and blot it off after a few minutes. Dried blood takes several rounds.

Urine. Blot, enzyme cleaner, cold water, then baking soda overnight for the smell. DreamCloud is specific that “heat bonds the proteins in urine to the fabric,” so keep hot water and hair dryers away. Urine is the stain most likely to have soaked through to the inner layers, which is why it gets its own page: our how to get pee out of a mattress guide covers fresh and old accidents, kids’ beds and pets.

Vomit. None of the cleaning guides we read addressed vomit specifically, so this follows the general biological-stain advice. Lift off solids with a spoon or a piece of card without pressing down, blot, treat with an enzyme cleaner, rinse-blot with cold water, dry, then use baking soda overnight for the odour. If the illness was a stomach bug, wash all the bedding hot straight away and wash your hands well afterwards.

Coffee, tea, wine and juice. Blot immediately with a dry cloth — speed matters more than product. DreamCloud’s general spill advice is cold water, then a little dish soap for sugary or coloured residue, and a light mist of white vinegar diluted 50/50 with cold water. Nectar’s ratio is 1 cup of vinegar to 1–2 cups of warm water for spot cleaning; we’d use cold for anything protein-based.

Oil, lotion and makeup. The exception to “start with water.” DreamCloud warns that “adding water to an oily stain pushes it deeper,” so sprinkle baking soda on first, let it sit, vacuum, then deal with the rest using a tiny amount of dish soap on a cloth.

The basic method works on every mattress, but the materials change how much moisture and heat you can get away with. Memory foam is the least forgiving, innerspring the most.

Memory foam: no soaking, ever. Nectar puts it plainly — memory foam mattresses “are not supposed to be soaked at all.” Foam acts like a sponge with no easy exit for water, so liquid that gets past the cover lingers and can lead to smells or mildew. Use a barely damp cloth, enzyme cleaner sprayed onto the cloth, and plenty of drying time. Don’t steam it; steam pushes hot moisture straight into the foam. And don’t unzip the cover to wash it: on Nectar and DreamCloud mattresses that alone voids the warranty, and many foam-mattress covers aren’t designed to be laundered and put back on. Our memory foam vs hybrid guide has more on how these beds are built.

Latex. Natural and synthetic latex is more resilient than memory foam but still shouldn’t be soaked. Use mild soap and cold water on a cloth, avoid bleach and solvents, and give it a long air-dry. If you chose latex for its natural materials — as many buyers of latex and organic mattresses do — you probably want to skip harsh chemical cleaners anyway, and enzyme cleaners or dish soap are gentle choices.

Hybrid. A hybrid has a coil core under several inches of foam, so clean the top exactly as you would a foam bed. The sides are often thinner fabric over coils; vacuum them well. Hybrids breathe better than all-foam beds, so they dry a bit faster, but the comfort foam on top is the part that matters for both cleaning and warranty.

Innerspring. Traditional coil beds with quilted or pillow tops tolerate a little more moisture, and an upholstery cleaner used sparingly is fine. The risk with over-wetting is rust on the springs and mildew in the padding. If yours is double-sided, clean both sides and flip it as part of the routine. Our mattress lifespan guide covers the full rotate-and-flip schedule, so we won’t repeat it here.

Mold on a mattress is a moisture problem first and a cleaning problem second. It usually shows up on the underside of a bed sitting on a solid platform or the floor in a humid room, or after a spill or leak that never dried properly. Black, green or grey speckling with a musty smell is the giveaway.

The EPA’s guidance is the honest answer most cleaning guides skip: “absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy,” because mold can grow into the crevices of the material and may be impossible to remove fully. A mattress is about as porous as household items get. Surface mildew on the cover that came from a single spill may wipe off; mold that has grown into the foam or padding generally can’t be cleaned out.

• Small surface spots on the cover: wear gloves and a mask, vacuum with a HEPA vacuum outdoors if possible, wipe with a cloth dampened in detergent and water, and dry completely. The EPA says most people can handle cleanup themselves when the area is less than about 10 square feet — a mattress is well under that, but it isn’t a hard surface, which is the bigger issue.
• Mold that returns, covers a large area, or has a strong smell from inside: replace the mattress. Anyone with asthma, allergies or a weakened immune system shouldn’t sleep on it.
• Skip bleach. The EPA does not recommend chlorine bleach as routine mold cleanup, and on a mattress it would mean soaking foam with a harsh chemical.

Prevention is easier. The EPA says to dry water-damaged items within 24–48 hours and to keep indoor humidity below 60%, ideally between 30% and 50%. For mattresses, that means using a slatted or ventilated base rather than a solid surface where possible, not putting a bed directly on a cold floor, and airing it out after a spill. A cheap hygrometer will tell you whether your bedroom is the problem.

Every mattress that has been slept on has dust mites. They feed on skin flakes and thrive in warm, humid bedding, and for people who are allergic, their droppings are a major trigger. You can’t eliminate them, but you can reduce them — and the reduction steps overlap almost completely with routine cleaning.

AAFA’s recommendations are concrete: cover mattresses and pillows in zippered allergen-barrier covers, wash sheets, blankets and pillowcases weekly in water of at least 130°F, keep home humidity between 30% and 50%, and vacuum your mattress every one to three months — more often if you don’t have a fully enclosing cover. AAFA also notes that “vacuuming alone is not enough to remove all dust mites and their waste,” because many live deep inside mattresses and carpets.

Here’s the part the allergy-product marketing leaves out. A Cochrane review of 54 trials with 3,002 people with mite-sensitive asthma found that chemical and physical mite-control measures, including mattress encasings, had no measurable effect on symptoms, medication use or lung function. The review is older, but it’s a useful reality check: cleaning and covers lower mite levels, and that’s worth doing, but don’t expect them to replace treatment from your doctor. If allergies are why you’re cleaning, see an allergist as well.

Practical upshot: an encasement or protector, weekly hot washes and a vacuum every month or two do most of the work. Steam cleaners and UV wands are popular for mites, but steam adds moisture to foam (bad), and we found no good evidence that consumer UV wands reach the mites living inside the mattress.

Bed bugs are a different problem from dirt. Cleaning won’t remove an infestation, and a botched DIY attempt can spread it to other rooms. First, confirm what you’re dealing with. The CDC lists the signs as rust-coloured blood spots on the mattress, shed skins, live bugs in the folds and seams, and a sweet, musty odour. Bites alone are unreliable, because they can take up to 14 days to appear. The CDC also says bed bugs “are not known to spread diseases to people,” which is worth knowing when you’re panicking at 2 a.m.

The EPA’s DIY guidance gives the main tools and their limits:

• Heat: wash and tumble-dry bedding and clothes on high heat. For the mattress itself, a steam cleaner can work if the steam is at least 130°F and doesn’t blow forcefully — the EPA suggests using a diffuser so bugs aren’t scattered. Don’t try to heat the room with the thermostat or space heaters; the EPA says that doesn’t work and is dangerous.
• Cold: small items can go in a freezer, but only if it reaches 0°F, and they need to stay there for three days.
• Encasements: a bed-bug-tested encasement traps any bugs inside the mattress and box spring so they die. The EPA says to “leave the encasements on for a year” and to buy one strong enough to last that long without tearing.
• Vacuuming: vacuum seams, bed frame, under the bed and all crevices, and change the bag after each use so bugs can’t escape.

When to call a professional. If you’ve confirmed live bugs, our advice is to call a licensed pest management professional sooner rather than later. The EPA says hiring an experienced professional “can increase your chance of success,” and pros have access to whole-home heat treatment that DIY can’t match. Treatment can take weeks to months, and the EPA advises inspecting at least every seven days and continuing checks for at least a year. If you rent, tell your landlord, since neighbouring units may need inspecting too.

Throwing it out? You often don’t need to — an encasement can save a mattress. If you do discard an infested mattress, the EPA says to slash or otherwise destroy it so nobody else takes it home, and check your city’s bulky-waste rules. Our disposal section covers recycling programs, which may refuse infested units.

The sources broadly agree: Sleep Foundation recommends cleaning your mattress “once every 6 months or so,” Nectar says about every six months, and DreamCloud suggests a full baking-soda treatment two to four times a year with a vacuum every one to three months. Spills and accidents get treated as they happen, whatever the schedule.

Our recommendation: deep clean twice a year, vacuum quarterly, and pair both with the rotation schedule so the mattress is already stripped when you rotate it. Clean more often — every three months — if you have pets on the bed, kids, allergies, or you sweat heavily at night. If you’re spring cleaning anyway, March and September make easy reminders.

It’s also worth doing a clean when you change seasons from heavy to light bedding, after any illness, and before guests use a spare bed that has been sitting unused. A spare-room mattress often smells musty simply because nobody has aired it in months.

Yes, in two ways — and both push you in the same direction: protect the mattress so it never needs aggressive cleaning.

Stains can void a claim. Every partner warranty we were able to read excludes staining. Saatva’s terms say the warranty “does not apply if the mattress has been stained, burned or otherwise abused.” Nectar and DreamCloud, which are sister brands with near-identical terms, exclude damage including “liquid damage, or stains.” Puffy excludes “stains, tears, burns, and discoloration that occur over time and/or are caused by you.” Bear’s warranty page (checked 27 October 2026) excludes stains and liquid damage where they cause the defect, and says removing the cover voids a claim. In practice, brands typically ask for photos with a claim, and a stained mattress can sink a claim for a genuine defect such as sagging.

Removing the cover can void it too. Nectar’s and DreamCloud’s mattress warranties list “any Mattress that has had the cover removed for any reason” as excluded. This catches people out, because a zipper looks like an invitation. It isn’t. Clean the cover in place.

Bedding has its own care rules. Nectar’s and DreamCloud’s bedding warranties, which cover their own protectors and pillows, exclude “normal soiling” and problems caused by “incorrect or inadequate maintenance, cleaning, or care,” and say care labels “must be followed at all times.” Wash protectors exactly as the label says.

Our take: put a waterproof protector on the day the mattress arrives — it’s the only thing that keeps a mattress stain-free, which keeps the warranty intact. Its cost is small next to the replacement value of any of the beds in our best mattress rankings. For more on what these “lifetime” warranties really cover, see the warranty section of our mattress lifespan guide, and the brand reviews for Saatva, Nectar, DreamCloud, Puffy and Bear.

When to stop cleaning and replace. Cleaning freshens a mattress; it can’t restore one. If it sags, smells from deep inside after repeated treatment, has mold growing into the foam, or is past its typical lifespan, the money is better spent on a new bed. Our how to choose a mattress guide walks through the decision, and timing the purchase around the best time to buy a mattress can save a few hundred dollars.