I am going to say something gross: I did not clean my mattress once in the first four years I owned it. Not once. Not even a vacuum. I changed the sheets every week and figured that was enough. Then I read that the average mattress doubles in weight over ten years from accumulated dead skin cells, dust mites, and their… waste. I stripped the sheets that same day.

Here is the good news: deep cleaning a mattress takes less than an hour and the supplies cost maybe five dollars. You need baking soda, a vacuum with an upholstery attachment, and some dish soap. That is basically it. Here is the whole process.

Step 1: Strip everything and vacuum (10 minutes)

Remove all bedding — sheets, mattress protector, pillowcases, everything — and throw it in the wash on hot. While that runs, vacuum the entire mattress surface with the upholstery attachment. Go slow. Press down firmly. Pay extra attention to the seams, tufts, and piping around the edges — those crevices are dust mite condos.

If your vacuum has a HEPA filter, use it. Regular vacuum filters let the dust mite particles blow back into the room. If you do not have a HEPA vacuum, open a window while you work.

Step 2: Baking soda deodorize (30 minutes)

Sprinkle baking soda all over the mattress — about one standard box for a queen, two-thirds of a box for a full, more for a king. If you want a fresh scent, mix in 5-10 drops of lavender or tea tree essential oil with the baking soda before sprinkling. Tea tree oil is naturally antimicrobial, which is a bonus for a mattress.

Let it sit for at least 30 minutes. The baking soda absorbs moisture, oils, and odors. If your mattress has any lingering smells — sweat, pets, that weird mustiness — the baking soda pulls it out. For really stubborn odors, leave it for an hour or more.

Step 3: Spot clean stains (10 minutes)

While the baking soda sits, tackle any visible stains. Mix hydrogen peroxide (3%), a drop of dish soap, and a pinch of baking soda into a paste. Apply it directly to the stain with an old toothbrush and scrub gently. Let it sit for 5 minutes, then blot with a clean damp cloth. Do not saturate the mattress — you want it damp, not wet. Moisture that soaks deep into the mattress leads to mold.

For yellow sweat stains: hydrogen peroxide and dish soap paste. For blood stains: cold water and hydrogen peroxide (never hot water, it sets blood). For urine: white vinegar in a spray bottle, spray generously, blot, then baking soda on top to absorb remaining moisture.

Step 4: Vacuum again (10 minutes)

After 30 minutes (or longer), vacuum up all the baking soda thoroughly. Go over every inch of the mattress. Any baking soda left behind will feel gritty when you put the sheets back on. The mattress should now smell like nothing — which is exactly what you want — and look noticeably cleaner.

Put on a mattress protector before the sheets. A good waterproof protector costs about $25 and adds years to your mattress’s life. It is a lot easier to wash a protector than to deep clean a mattress. I bought one right after that first cleaning and have not had to do a full deep clean since — the protector catches everything.