Grimy grout lines make an otherwise clean bathroom look dirty. Grout is porous, so soap scum, body oil, and mildew soak into the lines and turn them yellow, brown, or pink.
You almost never need to retile to fix that. A baking soda and peroxide paste handles most discoloration, while steam or oxygen bleach reaches the set-in stains a surface scrub leaves behind.
Below are the homemade recipes, the deep-cleaning methods that work on old mold, and the drying habits that keep shower grout white once you get it there.
Key Takeaways
- DIY paste: Mix 1/2 cup baking soda, 1/4 cup hydrogen peroxide, and 1 teaspoon dish soap, spread it on the grout, and let it sit 10 minutes before scrubbing.
- Deep cleaning: Steam or oxygen bleach (sodium percarbonate) lifts set-in mold and mineral scale that a surface scrub cannot reach.
- Avoid damage: Keep vinegar off unsealed grout, marble, travertine, and limestone, because the acid etches stone and weakens cement grout.
- Maintenance: Squeegee the walls after every shower, run the exhaust fan, and reseal cement grout with a penetrating sealer once or twice a year.
What Is the Best Homemade Grout Cleaner?
The best homemade grout cleaner is a paste of baking soda, hydrogen peroxide, and a little dish soap. The baking soda gives you a mild abrasive that lifts buildup without scratching tile or grout, the peroxide bleaches the color out of the stain, and the soap cuts the greasy film soap scum leaves behind. Everything you need is probably already in the pantry, and it costs a fraction of a dedicated cleaner.
What You’ll Need
Gather these supplies before getting started:
- Solvents: Liquid dish soap and hydrogen peroxide.
- Abrasive: Baking soda.
- Safety gear: Protective rubber gloves.
- Tools: Small squeeze-top container or bowl.
Steps to Clean Grout with Homemade Grout Cleaner
Safety First
Put on your protective gloves. While hydrogen peroxide is mild, it can irritate open cuts or sensitive skin.
Take your squeeze bottle or mixing bowl and make sure it is free of dust. Pour in half a cup of baking soda and a quarter cup of hydrogen peroxide, then add one teaspoon of liquid dish soap.
Shake or stir until it forms a smooth paste. Hydrogen peroxide is water with an extra oxygen molecule, and against the mild alkalinity of baking soda it releases that oxygen, which is what loosens organic grime and bleaches color out of a porous surface.
Squeeze or spread the paste straight onto the grout lines. Give it at least 10 minutes to work, then scrub with a stiff nylon brush and rinse with hot water. If the line is still gray after one pass, apply it again and leave it longer rather than scrubbing harder, since dwell time does more than pressure.
How Do You Clean Grout in the Shower?
You clean shower grout by matching the cleaner to the stain: vinegar for light soap scum on sealed grout, a baking soda paste for general grime, and hydrogen peroxide for yellowing. Work one wall at a time so nothing dries before you rinse it.
With Vinegar
Vinegar is a classic acidic cleaner, and it is only safe on sealed grout with ceramic or porcelain tile.
Fill a spray bottle with equal parts warm water and white vinegar. Spray the grout lines generously, let it dwell about five minutes, then scrub with a stiff-bristled brush and rinse.
Important
Never use vinegar on unsealed grout, travertine, limestone, or marble. The acid eats away at the stone and weakens cement grout. If you do not know whether your grout is sealed, drip water on it: if the water soaks in and darkens the line, it is unsealed, so skip the vinegar.
With Baking Soda
Baking soda is the safest choice when you do not know whether your grout is sealed, because it is a mild alkaline abrasive that scrubs off surface stains without being harsh enough to scratch tile or grout.
Mix baking soda and water into a thick paste and apply it to the lines. For extra lifting power on sealed grout, spray the vinegar solution above onto the paste.
The mixture fizzes as the two react. Once it stops, scrub the lines with a brush, rinse thoroughly, and wipe dry so the loosened dirt does not settle back in.
With Hydrogen Peroxide
Hydrogen peroxide is the pick for yellowed or dingy grout that is not actually dirty on the surface. It is safe on both sealed and unsealed cement grout, and you can use it straight from the bottle or thicken it with baking soda so it clings to a vertical line instead of running down the wall.
With The Pink Stuff
The Pink Stuff is an abrasive cleaning paste that works well for spot-treating a few stubborn lines. It is also handy for cleaning shower tiles at the same time.
Scoop a small amount onto a damp sponge or an old toothbrush and work it into the grout in circular motions. Rinse thoroughly, and keep it off polished stone, since it is more abrasive than baking soda.
How Do You Deep Clean Shower Grout?
Deep clean shower grout with steam or oxygen bleach, then reseal the lines. Both methods reach into the pores where set-in mold and mineral scale live, which is exactly where a surface scrub cannot go.
With Oxygen Bleach
Oxygen bleach (sodium percarbonate) uses oxygen bubbles to lift stains without the toxicity of chlorine bleach, and it will not discolor colored grout.
Mix three tablespoons of powdered oxygen bleach into a bucket with two gallons of warm water. Use a sponge to saturate the grout lines completely, let it sit 15 minutes so the oxygen can work, then scrub lightly and rinse. Reapply on a badly stained shower floor rather than mixing it stronger.
With Commercial Cleaner
Sometimes you need a dedicated product. Look for an alkaline grout cleaner rather than an acidic one, since alkaline chemistry cuts the body oil and soap residue that make up most shower grime, and acids attack cement grout and stone.
Read the label before you start. Many commercial cleaners are concentrated and need dilution, and none of them should be combined with another cleaner.
With Steam
Steam cleans grout without chemicals: the heat and pressure reach into the pores.
Start by sweeping or vacuuming the area to remove loose debris. Dirt and hair can clog the steamer brush.
Attach a small nylon or brass brush to the steam lance. Apply steam directly to the grout line while scrubbing gently, and work in small sections so nothing dries before you wipe it.
Wipe the dirty water up immediately with a microfiber cloth or mop. Let it dry in place and the same dirt settles straight back into the pores.
With Chlorine Bleach
Safety Note
Chlorine bleach creates toxic fumes. Open windows, turn on the fan, and wear old clothes. Never mix bleach with vinegar, which makes chlorine gas, or with ammonia, which makes chloramine gas, according to the CDC; the only thing safe to add to bleach is water (1).
Use this as a last resort, and only on white grout. Dip a brush into diluted chlorine bleach, scrub the stained areas, then rinse immediately and thoroughly, because bleach left sitting degrades the grout structure over time.
With Grout Pen or Renewal
If cleaning fails, recolor instead. Grout pens and renewal paints sit on top of the existing grout and mask a permanent stain.
Clean and dry the area completely first, then trace the lines with the pen. This is a cosmetic fix, so it hides a stain but does nothing for grout that is crumbling underneath.
How Do You Keep Shower Grout Clean?
Keep shower grout clean by drying it fast and sealing it, since mold and mineral deposits both need standing water to build up. Preventing buildup takes far less work than scrubbing it off later:
- Squeegee daily: Pull the water off the walls after every shower so minerals and mold have nothing to settle into.
- Ventilate: Run the bathroom fan during your shower and leave it on afterward until the mirror clears.
- Seal regularly: Reapply a penetrating grout sealer every 6 months to 12 months in a busy shower, and every year or two in a lightly used guest bath.
- Weekly wash: Spray a mild cleaner and wipe the tiles down once a week so surface film never turns into a stain.
Speed matters more than scrubbing power here. According to the EPA, wet material that is dried within 24 hours to 48 hours usually will not grow mold at all, so a quick squeegee protects grout better than a monthly deep clean does (2). The EPA also puts the target for indoor air below 60% relative humidity, and ideally between 30% and 50%, which is the job the exhaust fan is doing.
When you do reseal, reach for a penetrating sealer rather than a topical or membrane one. Penetrating sealers soak into the grout and repel water from within, while a surface membrane can trap moisture behind it in a constantly wet shower and start to peel or discolor.
When Should You Replace Shower Grout?
Replace shower grout when it crumbles, cracks, or grows mold back within days of a deep clean, because those are structural failures that cleaning cannot fix. Grout usually lasts 15 to 20 years, though a slow leak behind the tile shortens that considerably.
Standard cement grout is porous, so it keeps absorbing water and staining as it ages. If the lines discolor again almost immediately after every deep clean, re-grouting with non-porous epoxy grout is the lasting fix, since epoxy resists water and mold and never needs sealing.
Watch for these two signs that you need to re-grout tile grouting:
- Crumbling texture: Press your fingernail into the grout. If it feels soft or powder falls out, the structure is compromised.
- Recurring mold: If mold keeps returning in the same spot immediately after cleaning, it may be growing behind the tile.
FAQs
Here are common questions about keeping your shower lines bright and clean.
In the End
Cleaning grout is mostly patience and picking the right cleaner for the stain. Start with the baking soda and peroxide paste, move up to steam or oxygen bleach for anything set in, and leave vinegar alone unless the grout is sealed and the tile is ceramic or porcelain.
Then protect the work. A squeegee after every shower, a fan that actually runs, and a penetrating sealer once or twice a year keep the lines white far longer than any single deep clean.
