How to Clean Grout Stained by Red Wine Vinegar
My husband spilled a whole bottle of red wine vinegar on our kitchen floor and into our light green grout which now looks black.
What can I use to bring back the color? (the tiles surrounding the grout is porcelain tile).
Try one using a mixture of baking soda mixed with the strongest hydrogen peroxide you can find.
I carry beauty salon grade hydrogen peroxide which is like 30%. Be careful with a high concentration as it can be harmful to your skin.
Mix them to a peanut butter consistency and then apply to the grout lines. Cover with plastic and tape the edges.
Let it dry out, maybe a day or two. If it's not drying out, try poking some holes in the plastic.
Once dry, remove and see the improvement. If it needs another application, do the procedure again.
It may take a few applications. If you are still not satisfied, you may need to colorseal the grout.
I hope this helps.