Mega Purple is a thick, grape juice concentrate that’s derived from Teinturer grapes (red grapes with dark skins and dark flesh; regular red grapes have dark skins and clear flesh). Its sole purpose is to “fix” red wines — specifically, to add color, and a massive wallop of sweet, fruit flavor (Mega Purple has a whopping 68% sugar content), because American consumers have become convinced that more color equals more flavor, and smooooooth (sweet) is better.