Airen grape was 23% of Spain’s total vineyards (1/3 of all grapes grown internationally, though decreasing) but primarily sold to Russia for the purpose of vodka production.  It’s an ancient grape from the 6th century Iberian Peninsula.  It’s a medium vigorous plant with late maturation and harvest with large clusters and often made into sherry, Spanish Brandy or left on the vine to produce raisins.  The seeds are used for grapeseed oil.    It’s drought and pest resistant and adapts to various soil types, which explains why it was widely planted after the phylloxera crisis.  In the 15th century, it was called “The King’s Laeren”.  As a wine it is dry, low alcohol, high acidity with simple mild flavor.