A mattress is the one piece of textile in your house that you cannot rinse out and cannot wring out. Whatever you pour on it stays in it. That is exactly why most home remedies go wrong here: you trade a stain for moisture in the core, and moisture in the core is where musty begins.
Short answer
Vacuum, treat marks spot by spot with as little moisture as you can, then let it dry right through.
Against dust mites it is heat and dry air that help, not a product. And yellow stains usually will not come out completely. Both are set out below.
Why wetting a mattress is the mistake
A mattress dries from the inside out, and that takes days.
Your bedding you can wash, a towel you can wring out. A mattress is neither. What goes in has to come out on its own, and with foam or a pocket sprung core that takes days.
A spray or a bowl of soapy water is out of sight on the surface within an hour, but the moisture that has gone through the ticking into the filling is still sitting there. Foam and latex give moisture up slowly, and a mattress lies flat on a base, so air only reaches it from one side. Every wet home remedy is a problem here: bicarbonate of soda, vinegar, hydrogen peroxide and detergent all soak in, and the part that does nothing simply stays. A mattress that stays damp inside for days smells different a week later, and not for the better.
So the rule is this: as little moisture as you can possibly manage, and always only on the spot, never over the whole surface. Call it cleaning or call it freshening up, you are tied to that same rule: the word changes from region to region, the moisture in the filling does not. That sounds like a restriction. It is the method. Then let it dry for as long as it needs, with the window open and the mattress standing on its side.
How to clean a mattress in four steps
Four steps. The third one is waiting, and you cannot skip it.
- Take the cover off and vacuum the mattress thoroughly. Use the upholstery nozzle and go slowly, over the sides and into the seam as well. That is where most of it gathers, and this is the step that gives you the most back.
- Treat marks one at a time with a barely damp cloth, not with a pouring hand. Blot from the outer edge towards the middle, otherwise you push the mark wider. Blot, never rub: rubbing drives it deeper into the fibre.
- Let it dry with the window open. Stand the mattress on its side against the wall if you can, so air gets at it from both faces. Reckon on a few hours.
- Turn it over and do the other face. The underside rarely gets any attention and gathers just as much. Only make the bed once the mattress feels dry everywhere.
Yellow stains on a mattress: what to expect
The honest answer is an uncomfortable one, and it helps you more than the pleasant answer does.
Yellow stains are dried sweat and urine. What you are looking at is not dirt sitting on top, it is colour that has gone into the fibre.
You can get the smell out and you can get the spot hygienically clean. The discolouration itself usually will not go. What you realistically end up with is lighter and odour free, and then covered with a washable protector so that nothing new is added to it.
If you want to try anyway, do it like this. Damp a cloth with lukewarm water and very little oxygen bleach, blot it on, leave it for ten minutes, blot after with a second damp cloth and let the spot dry straight away. Once, not three times. Work from the outer edge inwards, otherwise you end up with a pale ring around a dark patch, and that often shows up more than the stain itself.
Getting urine out of a mattress
Here the smell counts for more than the colour.
Fresh. The first minute is worth more than the hour after it. Take up as much as you can straight away with a dry cloth or a folded towel: press it down and hold it there, do not rub. Swap it for a clean one and repeat until nothing more comes up. Then blot after with a damp cloth and cold water, and blot it dry again immediately. Cold, because warmth sets the proteins.
Dried in. Then the problem is not the discolouration but the smell. It sits in the dried salts, and those become active again as soon as there is moisture. That is why an old patch suddenly smells again on a close summer day.
Against that smell an enzyme cleaner from the pet shop works better than any home remedy, because it breaks the protein residues down instead of laying a scent over the top of them. Apply it sparingly, leave it to work, blot it off, and give it a long time to dry.
What you should not do: flush the spot through to wash the smell out. It does not work, and the water only carries the smell further down into the filling where you cannot reach it. If it happens regularly, in a child's bed for example, a waterproof protector under the fitted sheet is the only measure that deals with it at source, and that protector goes in the washing machine. That is the entire reason to have one.
Dust mites in bed: what actually helps
The biggest subject around mattresses, and the one with the most half truths in it.
Dust mites live on skin flakes and they need moisture. Dealing with dust mites therefore means taking their moisture away. Dirt is not their habitat, a warm damp bed is. What demonstrably does something:
- Wash bedding at 60 degrees, every one to two weeks. At 30 degrees the mites survive the wash.
- Bring the humidity in the bedroom down. Below roughly 50 per cent it gets difficult for them. Ventilate in the morning and fold the duvet back.
- Mite proof covers, if somebody in the house is allergic. That is the measure with the best evidence behind it.
- Heat on the surface, with steam for example. This is the one place in this article where a machine does something that a cloth and a home remedy cannot.
What does little: mite sprays on the mattress, because they never reach the depth and they leave behind precisely the product that does not belong in there.
Should you vacuum a mattress or not?
The sources contradict each other here, and almost nobody tells you that.
Vacuuming lifts loose skin flakes and mite debris off the surface. That is good. At the same time the airflow whirls fine particles up, and if your vacuum has no fine filter it blows them straight back out at the other end.
The workable middle ground: do vacuum, but slowly and with a fine filter, and ventilate afterwards. If you are strongly allergic, it is better to let somebody else do the vacuuming. What you never do is beat the mattress: that puts exactly what you wanted rid of into the air of your room.
What bicarbonate of soda does on a mattress, and what it does not
The home remedy question in its purest form, and a question of names as well.
The names first, because they get mixed up. The white powder you see recommended everywhere is bicarbonate of soda, sodium bicarbonate, the same powder that is sold as baking soda. Soda crystals are something else: sodium carbonate, and far harsher. The difference is set out in soda crystals, bicarbonate of soda and baking soda. The harsh one has no business on a mattress in any case.
Bicarbonate of soda absorbs smell and a little moisture. That part works, and it is why the tip is so persistent. Sprinkle it on, leave it a few hours rather than overnight, then vacuum very thoroughly.
What it does not do: lift a mark out, kill mites or disinfect a mattress. And here is the point where it goes wrong: powder that you do not get completely back out stays in the ticking and in the foam, because the grains work their way down into the filling and a vacuum will not bring all of them back. So use it sparingly and dry, never as a paste with water.
Vinegar is a different case. Vinegar is strong on limescale and on grease, which is why it earns its place in the kitchen. Only there is no limescale in a mattress. What vinegar does do here is put moisture exactly where you do not want it. Hydrogen peroxide bleaches the ticking along with the mark, so a pale patch on a dark cover is quickly made.
Washing the cover of your mattress
The easiest of the questions, with two traps in it.
If the cover unzips, the wash symbol is usually on the label at the side. Most of them go at 60 degrees, and 60 is precisely the temperature at which mites do not survive.
First trap: not in the tumble dryer unless the label expressly allows it. Plenty of covers shrink far enough that you cannot get them back over the core.
Second trap: wash both halves together if the cover is a split one. Otherwise one side comes out of the wash just a shade lighter than the other.
If the cover is sewn in, a washable mattress protector is what is left to you. That is the sensible purchase around this subject anyway.
Freshening a mattress with steam
Why steam is the exception to the moisture rule.
This whole article says one thing: no moisture in your mattress. Steam is the exception, and that is not a sales line but a difference in physics. Steam puts heat into the top few millimetres and condenses there into very little water. The core stays dry.
A carpet glider clips onto the floor head: a flat attachment that slides over the fibres instead of sinking into them, so the head keeps moving and the steam is not pressed down into one spot.
Steam leaves the boiler at around 135 degrees and arrives at the surface at around 85 degrees. Almost no moisture stays behind, because steam is water in gas form and most of it has evaporated again before it reaches the filling. Heat also leaves nothing behind: no product soaking in, no scent laid over the top of the old one.
Work in slow, continuous passes and do not stand still anywhere. Afterwards leave the mattress for an hour with the window open before you make the bed again.
What steam will not do
A mark that has already soaked in will not come up with heat.
Steam freshens and it warms right through, but it lifts nothing out. For a mark that has soaked in you need suction: something that pulls the moisture and the dirt back up out of the fibre together. A steam cleaner does not have that, and it is not a shortcoming, it is a different machine.
More than that: heat sets protein stains, and blood, sweat and urine are protein stains. So treat those cold first and only then reach for the steam, never the other way round. For blood on textiles the order is in how to remove blood stains.
Two things you leave alone whatever happens: spraying stain remover on generously, because on a sofa you can rinse after and in a mattress it simply stays there. And making the bed while there is still moisture in it, because then you seal that moisture in under the fitted sheet.
What will not come out any more
The limit belongs in the answer.
Old yellow stains, discolouration from blood, and a mattress that has once been properly wet and then dried out slowly: those are permanent changes. Lighter yes, gone no.
If a mattress smells musty for good while it is dry, the problem is in the core and not in the cover. Then replacing it is more honest than carrying on treating it. A mattress can always be freshened up. A mattress cannot be repaired.
How to need this less often
A mattress gets dirty from moisture, and the moisture comes from you.
A person loses half a litre of moisture a night, and it goes straight through the sheet. So air the bed for half an hour every morning before you make it, with the duvet folded back. It is the cheapest maintenance there is.
Use a quilted underlay or a mattress protector under your fitted sheet as well: that one you can simply put in the washing machine, and it catches what would otherwise go into the ticking. Turn the mattress every season, so it wears evenly, and do not push the bed up tight against a cold outside wall, because the air stands still there.
Frequently asked questions
How do you clean a mattress properly?
Cover off and into the wash, vacuum the mattress thoroughly with the sides and the seams included, treat marks one at a time with a barely damp cloth and then stand it on its side to dry right through. As little moisture as you can possibly manage, because what goes in does not come back out.
How do I get yellow stains out of my mattress?
Usually not completely. Yellow stains are dried sweat and urine, and the colour sits in the fibre. You can make them lighter and take the smell away: a damp cloth with very little oxygen bleach, ten minutes, blot after, let it dry straight away.
How do I get urine out of a mattress?
Fresh: press a dry cloth down on the patch straight away and take up as much as you can, do not rub, swap it for a dry one and repeat, then blot after with cold water. Dried in, it is mainly about the smell in the salts, and an enzyme cleaner works better on that than any home remedy. Do not pour water on to dilute it, because that carries it deeper into the filling.
What does bicarbonate of soda do on a mattress?
It absorbs smell and a little moisture, and no more than that. It does not lift marks out and it does not kill mites. Sprinkle it on dry only, leave it a few hours rather than overnight and vacuum very thoroughly afterwards, because the grains sink into the filling and a vacuum will not retrieve all of them. Never as a paste with water.
What helps against dust mites in bed?
Washing bedding at 60 degrees, keeping the humidity below roughly 50 per cent, ventilating in the morning and folding the duvet back. If there is an allergy in the house, mite proof covers as well. Heat on the surface works too. Mite sprays do very little.
Can I steam a mattress?
Yes, and it is the one exception to the rule about not putting moisture into a mattress. Steam warms the top few millimetres and leaves no product behind. Work in slow passes with the flat carpet glider on the floor head and never stand still. It will not lift marks out: heat sets protein stains. So marks first, steam after.
How do I wash the cover of my mattress?
If it unzips, the wash symbol is on the label at the side. Most go at 60 degrees, and mites do not survive that. Not in the tumble dryer unless the label expressly allows it, or the cover will no longer fit over the core.
How often should I clean my mattress?
Vacuum it every two to three months, and the cover or protector every one to two weeks at 60 degrees. Turn it twice a year. Do that and it will almost never need a thorough treatment.
How long does a mattress need to dry?
After treating a spot with a damp cloth, a few hours standing on its side by an open window. If it has been properly wet, reckon on one to two days. Only make it up when it feels dry everywhere, and not while it still feels cool to the back of your hand.
When is a new mattress wiser than cleaning?
When it smells musty for good while it is dry. The problem is then in the core rather than in the cover, and no treatment is going to help against that.
Can I get a stain out of a mattress?
A fresh one usually yes, if you blot straight away and do not rub. A mark that has been sitting there a while needs suction to pull the moisture and the dirt back up together, and a steam cleaner cannot do that. Freshening a mattress is always possible. Repairing one is not, and an old mark is generally a repair job.
Do soda crystals help against smell in a mattress?
Temporarily, and it costs you more than it gives. The grains sink into the filling and a vacuum will not get all of them back out. Soda crystals are also far harsher than bicarbonate of soda, so there is more at stake if they stay in there. Airing works better and leaves nothing behind.
More around the house
A rug follows the same logic, except that you can pick a rug up and let it dry from both sides: how to clean a rug and carpet. Upholstery has an order of its own: how to clean a fabric sofa. Our cloths are over at microfibre cloths.