How to Deep Clean Bathroom Tile Grout

Grout is essentially a magnet for soap scum, body oils, and mold. Because it is porous, it acts like a sponge, absorbing grime deep into its cementitious matrix rather than letting it sit on the surface where a simple wipe would suffice. If your tile looks dingy even after mopping, the grout lines are the culprit. Deep cleaning grout is not about brute force; it is about chemical dwell time. By creating a paste that can cling to the vertical surfaces of your shower or floor, you allow the cleaning agents to break down the organic buildup before you ever touch a brush to it. When done correctly, the grout returns to its original color, restoring the look of your entire bathroom without the need for harsh, caustic chemicals.

1. Clear the Space First. Remove all rugs, toiletries, and shower caddies from the floor or shower stalls. Sweep or vacuum the tiles thoroughly to ensure you are scrubbing grime, not loose debris.
2. Mix Your Cleaning Weapon. Combine two parts baking soda with one part hydrogen peroxide in a small bowl. Stir until it reaches the consistency of a thick frosting that will stick to grout lines.
3. Coat the Grout Lines. Use a gloved finger or a soft brush to smear the paste directly onto the grout lines. Ensure an even, thick layer covers all darkened areas.
4. Let Chemistry Do the Work. Let the paste sit on the grout for at least 30 to 60 minutes. If the grout is heavily stained, let it sit for two hours to ensure the hydrogen peroxide has time to lift the discoloration.
5. Scrub Out the Grime. Use a stiff-bristle grout brush or an old toothbrush to scrub along the lines in a circular motion. Apply moderate pressure to lift the loosened grime out of the porous surface.
6. Rinse and Dry Completely. Wipe away the remaining paste with a damp microfiber cloth or rinse with clean water from a shower head. Buff the surrounding tiles dry to prevent water spots.