How to Clean Grout in Tile: 3 Methods That Actually Work

The grout between your tiles gets dingy faster than the tiles themselves — it’s porous, light-colored, and catches everything from soap scum to mildew. But the fix doesn’t require a pro or expensive equipment. Most grout cleaning takes 15–30 minutes and costs less than $10 in supplies you probably already have.

This guide covers three methods ranked by effort and cost: baking soda paste (cheapest, renter-friendly), oxygen bleach (stronger without the tile damage), and steam or commercial cleaners (for stubborn mold). I’ve used all three in my own house, and I’ll tell you honestly which problems each one solves.

What You’ll Need

Tools:

Old toothbrush or grout brush
Small bowl for mixing
Rubber gloves
Squeegee or clean towel
Spray bottle (for oxygen bleach method)

Materials (varies by method):

Baking soda — $2 for a box
Hydrogen peroxide (3% solution, optional) — $1–2
Oxygen bleach powder (OxiClean or Bar Keepers Friend) — $5–8
Commercial grout cleaner (Zep, Black Diamond) — $8–12
Handheld steam cleaner (optional, one-time cost $50–150)

Prerequisites:

Know whether your grout is sealed or unsealed (see below)
Clear counters and floor area around the tile
Ventilation if using any bleach-based product

Before You Start

Figure out what you’re dealing with: Spray a bit of water on the grout. If it beads up, your grout is sealed. If it soaks right in, it’s unsealed. Sealed grout tolerates stronger cleaners; unsealed grout is more sensitive to discoloration from harsh chemicals.

Test in a hidden spot first. Always try your chosen cleaner on a grout line behind the toilet or under a cabinet. Wait 10 minutes, rinse, and check for color change or damage. This matters especially if you have colored grout or natural stone tile.

Ventilation is required for any bleach-based method. Open a window and run the exhaust fan. I’ve cleaned grout with the door closed and regretted it — even oxygen bleach has fumes.

Step 1: Choose Your Method Based on the Problem

Surface dirt and light discoloration: Baking soda paste. This is maintenance cleaning — gentle, cheap, and safe for colored grout.

Moderate stains, soap scum, hard water deposits: Oxygen bleach (OxiClean, Bar Keepers Friend). Stronger than baking soda but won’t strip color like chlorine bleach does. This is my go-to for showers.

Heavy mold, mildew, or large areas: Steam cleaner or commercial grout cleaner. These penetrate deep into grout pores and kill mold spores instead of just scrubbing the surface. I use this when the bathroom hasn’t been deep-cleaned in months.

Step 2: Mix Your Cleaner (Baking Soda Method)

Combine 3 parts baking soda to 1 part water in a small bowl. Stir until thick enough to stay on a vertical grout line without dripping. For more cleaning power, swap the water for 3% hydrogen peroxide (same 3:1 ratio). The peroxide version works better on mildew but costs an extra dollar.

Make about a quarter-cup at a time — more than that starts drying out before you finish applying it.

Image suggestion: overhead shot of bowl with baking soda paste, measuring spoon visible

Step 3: Apply to Grout Lines

Homemade baking soda cleaning paste in white bowl next to old toothbrush — Photo by hello aesthe on Pexels

Use the toothbrush to spread paste directly onto the grout. Press it into the lines — you’re getting cleaner into the pores, not just the surface. Work in sections about 2 feet square so the paste doesn’t dry before you scrub.

For oxygen bleach: Mix per package directions (usually 1–2 tablespoons per cup of warm water), put it in a spray bottle, and spray the grout lines. Let it sit 5–10 minutes.

For commercial cleaners: Follow the label. Most tell you to spray, wait, then scrub.

Step 4: Let It Sit

Baking soda paste: 5–10 minutes.

Oxygen bleach: 10–15 minutes (check the package).

Commercial cleaner: Follow label time, usually 3–5 minutes.

Don’t let baking soda paste dry completely — if it turns chalky, mist it lightly with water before scrubbing.

Step 5: Scrub in Circular Motions

Use the grout brush or a stiff-bristled toothbrush in small circles along each line. You should see dirt lifting onto the brush. For stubborn spots, apply more paste and scrub harder, but if you’re scrubbing for more than 30 seconds on one spot with no progress, you’ve hit the limit of this method — move to a stronger cleaner or accept that it might be a permanent stain.

Image suggestion: close-up of hand scrubbing grout line with brush, visible contrast between cleaned and uncleaned sections

Step 6: Rinse Thoroughly

Wipe down with a damp cloth or sponge, rinsing frequently in clean water. For floors, a mop works. For walls, use a squeegee to pull water down into the tub, then wipe with a towel.

Get all the cleaner residue out — leftover baking soda or oxygen bleach will leave a white film once it dries.

Step 7: Dry and Inspect

Close-up of dark mold and stains in grout between bathroom shower tiles — Photo by mas_hha on Pexels

Use a clean towel or let it air-dry for 20 minutes. Look at the grout in good light. If it’s noticeably brighter, you’re done. If some lines are still dingy, repeat the process or move to the next-stronger method.

Verify It Worked

Run your finger along a cleaned grout line — it should feel smooth, not gritty. The color should be closer to the original shade (usually light gray or white unless you have colored grout). If you’re cleaning a shower, water should bead slightly on sealed grout after drying.

Troubleshooting

Problem: Grout is still discolored after two rounds of baking soda

The stain is likely below the surface. Try oxygen bleach or a commercial grout cleaner. If that doesn’t work, the grout may be permanently stained or need resealing.

Problem: Grout is turning white or fading

You used chlorine bleach on colored grout, or you used an acidic cleaner (like vinegar) on natural stone. This is permanent. The fix is to re-stain the grout or accept it.

Problem: Mold comes back within a week

You have a moisture problem, not a cleaning problem. The exhaust fan should run during and for 20 minutes after every shower. If mold keeps returning, you may have a leak or ventilation issue that needs a pro to assess.

Problem: Grout is crumbling or missing in spots

This isn’t cleanable — it’s structural. You need to regrout those sections. Small areas (under 10 linear feet) are DIYable with a grout saw and premixed grout, but larger areas or wet areas like showers should get a tile professional.

When to Call a Professional

Heavy mold that won’t budge after bleach treatment. You likely have moisture trapped behind the tile or a ventilation issue that cleaning won’t fix. A pro can assess whether you need regrouting, sealing, or HVAC work.

Grout is crumbling, cracking, or missing. Regrouting in wet areas is past hobbyist level. Get a tile setter.

Large floor areas (over 200 square feet). Professional grout cleaning services cost $200–400 and save you 8+ hours of scrubbing. They use truck-mounted steam systems that pull dirt from pores you can’t reach with a toothbrush.

Efflorescence (white powdery deposits) that keeps returning. This is salt leaching from behind the tile, usually a sign of water intrusion. A pro needs to diagnose the source before you keep cleaning the symptom.

Renter-Friendly Considerations

All three methods in this guide are reversible and leave no permanent residue — important for deposit protection. Baking soda and oxygen bleach rinse completely clean. Avoid silicone-based grout sealers unless your lease explicitly allows permanent alterations.

Take before-and-after photos with timestamps if you’re cleaning heavily stained grout before move-out. I’ve had landlords try to claim “damage” on grout that was dirty when I moved in. Photos with metadata shut that down fast.

FAQ

What’s the cheapest way to clean grout?

Baking soda and water. A $2 box cleans about 100 square feet of grout lines. Mix 3 parts baking soda to 1 part water, scrub with an old toothbrush, rinse. It works on surface dirt and light stains but won’t touch mold or deep discoloration.

Can you clean grout with baking soda?

Yes — baking soda paste (3:1 with water or hydrogen peroxide) is safe for all grout types, including colored grout. It’s mildly abrasive and slightly alkaline, which lifts dirt without bleaching. Let it sit 5–10 minutes, scrub, and rinse. For mold or heavy stains, you’ll need oxygen bleach or a commercial cleaner.

How often should you clean grout?

Wipe down high-traffic grout (showers, kitchen backsplashes) weekly with soap and water to prevent buildup. Deep-clean with baking soda or oxygen bleach every 1–3 months depending on use. If you squeegee after every shower and run the exhaust fan, you can stretch deep cleans to twice a year.

Does vinegar clean grout?

Vinegar is acidic and can etch or discolor grout over time, especially on natural stone tile (marble, travertine). It’ll cut soap scum on ceramic tile grout, but baking soda or oxygen bleach are safer and more effective. I don’t recommend vinegar for regular grout cleaning.

Grout cleaning is one of those jobs that looks harder than it is — most bathroom grout responds to baking soda and 20 minutes of scrubbing. If you’ve tried the gentlest method and it’s not working, move up to oxygen bleach before calling anyone. And if you’re dealing with mold that keeps coming back, fix the ventilation first; no amount of scrubbing beats a working exhaust fan.