Mimosa (cocktail) For other uses, see Mimosa (disambiguation). A Mimosa is a cocktail composed of equal parts champagne (or other sparkling wine) and chilled citrus juice, usually orange juice unless otherwise specified (e.g., a grapefruit juice mimosa). It is traditionally served in a tall champagne flute at brunch, at weddings, or as part of First Class service on some passenger railways and airlines.