1. Start by mixing baking soda with a small amount of water to form a thick paste.

2. Apply the paste generously over the moldy caulk, ensuring full coverage.
3. Allow the paste to sit for about 15 minutes to penetrate the mold.
4. Fill a spray bottle with white vinegar and spray it over the baking soda paste. The mixture will fizz, helping to lift mold from the caulk.
5. Use a small brush or old toothbrush to scrub the caulk gently, focusing on heavily stained areas.
6. Wipe away the residue with a clean cloth, and rinse the area with water.
7. Dry the caulk thoroughly to prevent further mold growth.
Why This Whitening Method Works
The combination of baking soda and vinegar is a time-tested cleaning hack. Baking soda’s abrasive nature helps physically remove mold, while vinegar’s acidity kills mold spores and prevents regrowth. The fizzing action when vinegar meets baking soda helps to dislodge mold particles, making them easier to scrub away. This method is not only effective but also environmentally friendly and safe for most surfaces.
Additional Tips for Maintaining Clean Caulk

To keep your caulk mold-free, ensure proper ventilation in areas prone to moisture. Use exhaust fans during and after showers, and wipe down wet surfaces regularly. Consider applying a mold-resistant sealant over the caulk to provide an extra layer of protection. Regular cleaning with mild detergents can also help prevent mold buildup.
Alternative Solutions for Moldy Caulk
If the mold is particularly stubborn or extensive, commercial mold removers can be used. These products are formulated to tackle tough mold stains but should be used with caution due to their chemical content. In cases where the caulk is severely damaged or deteriorated, replacement might be the best option. Silicone caulk, which is more resistant to mold, can be a good choice for new installations.
Conclusion and Final Thoughts
Whitening moldy caulk doesn’t have to be a daunting task. With the right materials and a bit of elbow grease, you can restore your caulk to its original brightness without resorting to replacement. My aunt’s method is a testament to the power of simple, natural cleaning solutions. By understanding the causes of mold growth and taking preventive measures, you can maintain clean, healthy caulk in your home.