"Gran Reserva" is a term primarily used in the wine industry, particularly in Spain. It indicates a high-quality wine that has undergone extensive aging. For red wines, this typically means at least five years of aging, with a minimum of two years in oak barrels. For white wines, the aging requirement is usually four years, with at least six months in oak. The designation is a mark of excellence, often associated with prestigious wine regions like Rioja and Ribera del Duero. Wines labeled as "Gran Reserva" are expected to have complex flavors and aromas, making them sought after by collectors and enthusiasts.