Clean Grout Between Tiles

Grout turns dark not because it's dirty in the traditional sense, but because it's porous. Every shower, every mop bucket, every barefoot step deposits microscopic particles into those tiny cavities. Over months, that accumulation becomes the gray-brown shadow between your tiles. The good news: grout cleaning is chemistry, not elbow grease. The right combination of alkaline cleaner and mechanical agitation lifts years of buildup in a single afternoon. Most commercial grout cleaners work, but they're expensive and harsh. The baking soda and peroxide method costs three dollars, smells like nothing, and produces results identical to products that cost twelve times more. The trick is patience. Let the paste do the work. Scrubbing harder doesn't clean better—scrubbing after the chemistry has broken down the oils and minerals does.

1. Clear the Surface First. Remove everything from the floor or shower. Sweep or vacuum to eliminate loose dirt and hair. Any debris left on the surface will turn into mud once you start working with wet paste, making the job messier and less effective.
2. Mix Fresh Paste Now. In a small bowl, combine half a cup of baking soda with just enough hydrogen peroxide to form a thick paste—roughly the consistency of peanut butter. Stir until smooth. The paste should hold its shape but spread easily with a brush.
3. Pack Paste Into Lines. Use an old toothbrush or grout brush to work the paste directly into the grout lines. Don't spread it thin like butter—pack it into the grout with small circular motions. Cover all the grout you plan to clean in this session. For large areas, work in sections no bigger than four by four feet.
4. Let Chemistry Do Work. Leave the paste on the grout for 10 to 15 minutes. You'll see slight fizzing as the peroxide reacts with organic material. Don't let it dry completely—if it starts to look chalky, mist lightly with water from a spray bottle.
5. Scrub With the Grain. Using a stiff-bristled brush, scrub along each grout line with firm, steady strokes. Work with the line, not across it. The paste should have loosened the grime; you're removing it now, not grinding it out. Rinse the brush frequently in clean water.
6. Rinse Until Water Runs Clear. Wipe away the paste and loosened grime with a damp sponge or cloth, rinsing frequently. For floors, use a mop and bucket with fresh water. Change the water at least once. The grout should look noticeably lighter. Any remaining haze will dry clear.
7. Hit Stubborn Spots Again. For grout that's still discolored, make a second batch of paste and repeat the process on problem areas only. Some stains—especially rust or hard water deposits—may need a dedicated cleaner, but the peroxide method handles 90 percent of typical grime.
8. Inspect After Drying. Allow the grout to dry completely—at least two hours. Wet grout looks darker than it is. Once dry, inspect your work in good light. The lines should be uniform in color and several shades lighter than when you started.