Tile Grout Brightener

Steps

1. In a small bowl, combine 1/2 cup of baking soda with 3 tablespoons of hydrogen peroxide. Stir until a thick paste forms.
2. Add 1 tablespoon of lemon juice and 1 teaspoon of liquid dish soap. Mix thoroughly until the paste is smooth and spreadable.
3. Using an old toothbrush or a small grout brush, apply the paste directly onto discolored grout lines. Press the paste firmly into the grout.
4. Let the paste sit on the grout for 15 to 20 minutes. For severely stained grout, cover the paste with plastic wrap to keep it moist and leave for up to 30 minutes.
5. Scrub the grout lines vigorously with the brush, working in small sections. Reapply paste to stubborn areas as needed.
6. Wipe the area clean with a damp sponge, rinsing the sponge frequently. Follow with a dry cloth to prevent moisture from settling back into the grout.

Why It Works

Grout is porous cement that absorbs moisture, soap residue, and mildew over time, causing it to darken. Hydrogen peroxide is an oxidizing bleach that releases oxygen radicals when it contacts organic stains, breaking apart the pigmented molecules that cause discoloration. Lemon juice adds citric acid, which dissolves mineral deposits trapped in the grout surface. Baking soda provides both gentle abrasion to scrub away loosened grime and an alkaline boost that helps emulsify greasy residue. The dish soap reduces surface tension, allowing the active ingredients to penetrate deeper into the porous grout.

Tips

• For routine maintenance, spray grout lines with hydrogen peroxide after cleaning and let it air dry. This prevents mildew from reestablishing.
• After brightening, seal grout with a penetrating silicone-based sealer to protect it from future staining and moisture absorption.
• This paste works best on white or light-colored cement grout. Do not use on colored grout as the peroxide may bleach it unevenly.
• Replace your toothbrush with a stiff-bristled grout brush for large areas — it saves significant time and wrist strain.