How to Deep Clean a Mattress: Stains, Smells and Dust Mites

The short answer

Strip the bed, vacuum the whole mattress with an upholstery attachment, spot-clean stains by blotting (never soaking) with an enzyme cleaner or mild dish-soap solution, then sprinkle baking soda over the surface, leave it for several hours and vacuum it up. Let the mattress dry completely before making the bed, and fit a washable waterproof protector.

Blot, don't scrub, and use as little liquid as possible — moisture inside a mattress causes mildew.

Enzyme cleaners work best on sweat, urine and other body-fluid stains.

Always use cold water on blood; hot water sets it.

Deep clean every six months; a protector does most of the work in between.

A mattress collects sweat, skin flakes and dust every night, and most of us never clean it. You don’t need special machines. A vacuum, some baking soda and the right stain cleaner handle almost everything.

What you’ll need

Vacuum with an upholstery or crevice attachment
Baking soda (about 250 g / 1 cup for a queen mattress)
Enzyme cleaner for body-fluid stains
Mild dish soap and cold water
Clean white cloths or paper towels
A fan or an open window to help it dry

Step-by-step: deep cleaning a mattress

1. Strip the bed and wash everything

Remove the sheets, pillowcases and mattress protector. Wash them on the hottest setting their care labels allow. This takes care of most of the dust and skin cells before you start.

2. Vacuum the whole mattress

Go slowly over the top, sides and seams with the upholstery tool. Use the crevice tool along piping and around any buttons, where dust gathers. Slow passes lift more than fast ones.

3. Spot-clean stains

Treat stains one at a time, working from the outside of the stain inwards so it doesn’t spread. Use as little liquid as you can — a damp cloth, not a wet one.

Sweat and yellow marks: spray lightly with enzyme cleaner, leave it for the time on the label, then blot dry.
Urine: blot up as much as you can first. Apply enzyme cleaner generously enough to reach as far as the urine did, leave it to work, then blot. Enzymes break down the compounds that cause the smell rather than masking it.
Blood: use cold water only. Dab with a cloth dampened in cold water and a drop of dish soap, then blot. Hot water sets blood stains.
General marks and spills: mix a few drops of dish soap in a cup of cold water, dab with a cloth, then blot with a clean damp cloth to remove the soap.

Patch-test any cleaner on a hidden spot first, and follow your mattress maker’s care label if it gives different instructions.

4. Deodorize with baking soda

Once any damp patches are dry to the touch, sift a thin, even layer of baking soda over the whole surface. Leave it for at least a few hours — overnight is better if you have somewhere else to sleep. Vacuum it up thoroughly.

5. Dry and air it out

Open the windows or run a fan, and give it sunlight if you can. Don’t remake the bed until every cleaned spot is completely dry, as trapped moisture can lead to mildew.

6. Rotate the mattress

Turn it head-to-foot to even out wear. Flip it only if it’s a two-sided mattress.

Keep it clean for longer

The single best thing you can do is fit a washable waterproof mattress protector. It stops sweat and spills reaching the mattress, and you can wash it far more easily than you can clean foam.

Task	How often
Wash sheets and pillowcases	Weekly
Wash mattress protector	Every 1–2 months
Vacuum mattress	Every 1–3 months
Deep clean (steps above)	Every 6 months
Rotate mattress	Every 3–6 months

When cleaning isn’t enough

If a mattress smells musty after cleaning, has visible mold, or still has a strong urine smell after two enzyme treatments, the problem is deep inside the filling. At that point, professional cleaning or replacement is usually the better option. Mattresses also tend to lose support well before they look worn out — sagging and waking up stiff are signs it’s time.

The bottom line

Vacuum, spot-clean with as little liquid as possible, deodorize with baking soda, and let it dry fully. Then put a protector on it so the next deep clean is an easy one.

Common questions

How often should you clean a mattress?

Vacuum it and treat any stains every six months, or whenever you change seasons. Wash the mattress protector every one to two months, and bedding weekly.

Does baking soda really clean a mattress?

Baking soda absorbs odors and a little surface moisture. It doesn't remove stains or kill dust mites on its own, so use it after vacuuming and spot-cleaning, not instead of them.

Can I steam clean a memory foam mattress?

It's best not to. Foam absorbs moisture and is slow to dry, which can lead to mildew, and heat can affect some foams. Check the manufacturer's care label; most recommend spot cleaning only.

How long does a mattress take to dry after cleaning?

A lightly spot-cleaned area usually dries within a few hours with good airflow. Open windows, run a fan, and don't put bedding back until the spot feels completely dry.

Should I flip or rotate my mattress?

Rotate it head-to-foot every three to six months to even out wear. Only flip it if it's a two-sided mattress — most modern ones have a single sleeping side.