Question: how much hydrogen peroxide to add to wine?
Answer: The correct amount to add will depend on the sulfite level in the wine, an amount you cannot deduce except by chemical analysis. However, for the typical wine at 80 mg/L sulfites, 1 milliliter (~ 1/4 teaspoon) of 3% hydrogen peroxide, the form sold in pharmacies, will remove the sulfites in one bottle of wine.