Things You'll Need
Hot tap water
Tannins are a naturally occurring organic chemical common in grapes, chocolate, beans, corn and tea. Tannin stains are difficult to clean from many surfaces and require immediate attention and specific process. Grape juice has high tannin content and the potential to stain walls permanently. Stains on drywall with gloss or semigloss paint are less difficult to remove than other treatments. Pay attention to detail to avoid damaging the drywall while removing the grape juice stains.
Pat the stain with baking soda or talcum powder as soon as possible after it occurs. Let it sit on the stain for 10 to 15 minutes to absorb as much grape juice as possible.
Draw 1 gallon of very hot tap water into a bucket and add 3 tbsp. of dishwasher detergent.
Clean the stain with a large cellulose sponge liberally moistened with the hot water and detergent solution. Wipe from the top of the stain to the bottom to avoid streaks running down the wall.
Rinse the stain by sponging it with a solution of 1 part vinegar to 2 parts hot water. If the stain remains, continue to the next step.
Mix equal parts of warm water and ammonia, then use the sponge to clean the wall.
Place newspaper on the floor up against the wall to avoid getting dirty water on the floor while cleaning the wall. Have plenty of paper towels to absorb unintended spills.
Do not use natural soaps because they set the stain. Check the label on dishwashing detergents to make certain they don't contain soap. Scrub the wall gently with a non-abrasive sponge to avoid rubbing off paint.