While both drinks contain mint and sugar, the rest of the ingredients are different: - A mint julep calls for bourbon, whereas as mojito is made with rum. - And, a mint julep is made with simple syrup, while a traditional mojito is made with granulated sugar and club soda. - A mojito is made with lime juice, and a mint julep has no citrus added. - A mint julep is garnished with mint, a mojito with a slice of lime.