(BBCNews) - In the past 20 years there has been a revolution in the Argentine wine industry, driven partly by the success of one of a grape that in many countries is used only for mixing - the rich, velvety Malbec. One is small, dark and juicy. The other is loose and sandy, blasted by scorching sun during the day and cooled by mountain air at night. The Malbec grape and the soil of the western Argentine province of Mendoza were introduced to one another in the middle of the 19th Century.