How to Clean Grout and Tile (and Keep It White)

Your tile can be spotless and the room still looks dirty — because the eye goes straight to the grimy gray lines between the tiles. Here's the good news: most discolored grout isn't stained, it's coated — a film of soap scum, body oil, and dust that a stiff brush and the right paste will lift right off. This guide walks you through cleaning grout and tile the safe way, without wrecking the grout or your lungs, and how to keep the lines white once you've won them back.

What you'll need

• Baking soda
• White vinegar (for tile and sealed surfaces — see the safety note below)
• Hydrogen peroxide (3%, the drugstore kind) for tougher grout
• A stiff-bristle grout brush or an old toothbrush
• Dish soap
• A spray bottle
• Two microfiber cloths and a bucket of warm water
• Rubber gloves and an open window or fan

One safety rule first: never mix bleach with vinegar or with any ammonia-based cleaner. The combination releases toxic chlorine gas. Pick one cleaner, rinse well, and ventilate the room while you work.

Step 1 — Dry-sweep and pre-rinse

Wipe or vacuum the tile so you're not grinding loose grit into the grout. Then rinse the area with warm water. Cleaning agents work better on a surface that's already damp and free of surface dust, and the pre-rinse tells you which lines are genuinely dirty versus just dusty.

Step 2 — Make a baking-soda paste

In a small bowl, mix baking soda with enough water to form a thick paste — about three parts baking soda to one part water. Baking soda is a mild abrasive, so it scours the film off grout without scratching glazed tile. For everyday bathroom grime, this alone does most of the work.

Spread the paste directly along the grout lines with your fingers or an old spoon. Don't be shy — you want the lines fully covered.

Step 3 — Activate and scrub

Fill your spray bottle with white vinegar and lightly mist the paste. It will fizz; that reaction helps loosen buildup and lets the mixture cling to vertical grout. Let it sit for 5 to 10 minutes so it can do the work before you do.

Then scrub each line with your grout brush, working in short back-and-forth strokes along the line, not across it. An old toothbrush gets into corners and around fixtures. You'll see the brush turn gray fast — that's the coating coming up, not the grout wearing away.

Important caveat: vinegar is acidic. It's fine on ceramic and porcelain tile and on epoxy grout, but it can etch natural stone (marble, travertine, slate, limestone) and, over many repeat uses, degrade unsealed cement grout. If your tile is natural stone, skip the vinegar entirely — use the baking-soda paste with plain water, or a cleaner labeled stone-safe.

Step 4 — For stubborn or moldy grout, step up to peroxide

If lines are still dark after scrubbing, they may have a light mildew stain rather than a coating. Make a fresh paste of baking soda and 3% hydrogen peroxide instead of water, spread it on, and give it 10 to 15 minutes. Hydrogen peroxide is a gentler, safer whitener than bleach and won't gas you out of the room. Scrub again, and repeat once if needed.

For a whole shower, add a squirt of dish soap to a spray bottle of warm water as your general tile cleaner — it cuts the body oil that feeds the film in the first place.

Step 5 — Rinse thoroughly and dry

This step is the one people skip, and it's why the grime comes back fast. Wipe the whole area down with a clean, damp microfiber cloth, rinsing it often, until no paste residue remains. Leftover baking soda dries to a white haze and actually attracts new dirt. Finish by drying the tile and grout with a second dry cloth — a dry surface stays clean far longer than an air-dried one.

Keep it from coming back

The lines you just fought for will stay white a lot longer with a few small habits:

• Squeegee or towel the shower walls after use. Most grout discoloration is soap scum and mildew that grow on standing moisture. Thirty seconds of wiping beats an hour of scrubbing later.
• Run the bathroom fan during and for 20 minutes after every shower to pull humidity out. Mildew can't establish on a surface that dries quickly.
• Do a light weekly wipe with your dish-soap-and-water spray so film never has time to build into a coating.
• Reseal cement grout once a year (or when water stops beading on it). A fresh sealer keeps grime on the surface where it wipes away, instead of soaking into the porous grout.
• Skip the wire brush and heavy-grit scouring pads on grout lines — they wear away the grout and make it soak up dirt faster next time.

Quick FAQ

Can I just use bleach? You can spot-treat white grout with a diluted bleach solution for mildew, but never combine it with vinegar or ammonia, always ventilate, and keep it off colored grout and natural stone. Hydrogen peroxide is the lower-risk whitener for routine use.

Why does my grout look dirty right after cleaning dries? That's almost always leftover cleaning residue drying to a haze. Rinse more thoroughly and buff dry.

My grout is cracked or crumbling — will cleaning fix it? No. Cleaning won't repair failed grout; that needs regrouting. But clean, sealed grout is far less likely to crack from trapped moisture.

Grout is one of those jobs that's satisfying once and tedious forever — which is exactly why it's a core part of a full deep clean, where a crew handles the tile, the fixtures, and everything else you'd rather not scrub on a Saturday. If your bathroom is part of a bigger reset, it's worth pairing this with the full deep cleaning checklist, and when you'd rather hand it off entirely, a visit is bookable online in a couple of minutes.