How to Get Red Wine Out of Marble
Red wine on marble is two problems at once: pigment stain and acid etch risk. Move fast, but do not reach for acidic cleaners.
Blot first. Do not scrub. Do not use vinegar, lemon, or general stain remover on marble.
First five minutes
Blot the spill with a clean white towel. Press down and lift. Do not wipe in circles, because that spreads pigment and can grind grit into the finish.
Once the liquid is up, clean with pH-neutral stone cleaner or mild dish soap and water. Rinse lightly and dry. If the stone still shows pink or purple, move to a poultice.
Poultice method
Mix baking soda and water into a paste, spread it about 1/4 inch thick over the stain, cover with plastic wrap, and tape the edges. Leave it for 24 hours, then uncover and let it dry before removing.
The poultice pulls pigment out as it dries. Repeat once if the stain improved but did not disappear.
If the spot is dull
A dull spot means the acid in the wine etched the marble. That is not a stain anymore. It is a change in the finish. A poultice may remove color, but it will not restore polish.
Small etches can sometimes be improved with marble polishing powder. Larger or obvious etches need a stone restoration pro.