To get your old shower grout white again, use a paste of baking soda and hydrogen peroxide for tough stains or baking soda and vinegar for general cleaning, scrub with a brush, let it work, then rinse thoroughly; for mold, use a dedicated mould killer first, ensuring good ventilation and gloves. Always test in an inconspicuous area and consider applying a grout sealer afterward to keep it cleaner longer.
You generally should not grout directly over old grout for longevity and adhesion, as it often leads to cracking and peeling; instead, you must first remove a significant portion (at least 2mm) of the old grout, thoroughly clean the area, and then apply the new grout to ensure proper bonding and a lasting finish. Special rejuvenation grouts or epoxy grouts might require less removal, but scraping out most of the old material is the best practice for standard grout.
How to Clean Yellowing Grout
Baking Soda and Peroxide Mixture
Some professionals swear by a simple mixture of baking soda and peroxide to clean grout. Hydrogen peroxide is an acid, and baking soda is a base. Mixing the two creates a reaction that can penetrate the grout lines and free dirt and debris.
Causes of How Grout Turns Yellow
Hard water exposure is one of the main reasons why grout turns yellow. Constant exposure to minerals such as calcium, magnesium, and iron causes discoloration. A practical solution for this problem is to use water softeners to reduce the mineral content.
While grout pens are not a permanent solution to some grout issues, they're still an affordable and easy way to help you transform your home. Just be sure that you choose a grout pen in a color that works for your style, the room itself, and the tile.
If your grout is starting to show signs of wear and tear or is cracked or damaged, you can repair it without removing the old grout entirely. This can save you time and money, and it can also be less disruptive to your home.
Regrouting is the best option when tiles and grout begin to show signs of discoloration or the stains are so deep that they cannot be removed. As grout ages, it naturally deviates from its original color. If the white grout turns yellow or is covered with stains, you must regrout very soon.
Below are some of the things you should avoid using when cleaning grout.
Hydrogen peroxide (H₂O₂) is a mild antiseptic and oxidizing agent that breaks down organic stains, mold, and bacteria. Its oxygen-based bleaching action makes it effective for brightening grout lines—especially in high-moisture areas like Atlanta bathrooms, kitchens, and tiled entryways.
I want to actually clean my grout. Magic erasers get the job done, and they do it quickly and relatively painlessly. Technique-wise, I usually cut my standard size magic eraser in half, wet it to slightly more than damp, and scrub the grout line as I squeeze gently.
Professional cleaners use a mix of commercial cleaners (like CLR, Kaboom, or specialized pH-neutral formulas) and DIY solutions (vinegar/dish soap/baking soda) for soap scum and hard water, along with tools like microfiber cloths, non-abrasive sponges, grout brushes, and squeegees for various surfaces, ensuring cleaners match the material (avoiding acid on natural stone).
Hydrogen peroxide – a strong but safe alternative to bleach, is great for cleaning floor tile grout and tackling mould, especially in bathrooms. However, it may lighten coloured grout over time. Steam cleaning is a chemical-free method that effectively removes dirt from grout without scrubbing.
4 of the Most Common Regrouting Mistakes
Take bleach and baking soda, mix them and make a thick paste with a toothpaste-like consistency. Apply it on grouts and let it work for 15 minutes. Start scrubbing and then rinse it with water and let it dry.
Using the pen
It's ridiculously easy. Paint over the offending, grubby grout with the pen. That's it. The ink will cover the muck and restore the grout to its sparkling former glory.
Waterproof and Anti-Mould
It is also waterproof and dries after just 60 minutes, making it ideal for showers.
To get white grout white again, use a baking soda and vinegar paste for a natural scrub, a hydrogen peroxide and baking soda paste for tougher stains, or even a bleach/oven cleaner application (with caution) for stubborn mold/grime, scrubbing with an old toothbrush and rinsing thoroughly; for a lasting fix on permanently dingy grout, use a grout pen or colorant after cleaning.
Professionals use a multi-stage approach for cleaning grout, combining alkaline degreasers, steam cleaning, and high-pressure hot water extraction for deep cleaning, often using specialized brushes and sometimes acid washes for tough stains, plus tools like grout brushes, microfiber cloths, and sometimes powerful machine scrubbers for large areas, always ending with thorough rinsing and drying. They might also use oxygen bleach for brightening or specific grout cleaning powders for tough discoloration.
The Pink Stuff
Simply rub and scrub, and then rinse with hot water. As a mildly abrasive cleaner, the paste has a little grit to it, which helps scrub away dirt and debris from grout and surfaces.