Flor

Flor meaning in Sherry and wine

Flor is a naturally occurring film of yeast (Saccharomyces cerevisiae var. capensis) that forms spontaneously on the surface of certain fortified wines, most notably Fino and Manzanilla Sherries from Spain’s Jerez region. This delicate, cream-colored biological veil develops when wine is aged in partially filled barrels (typically 85% capacity) at alcohol levels between 15-15.5%, creating an anaerobic environment beneath the film. The flor consumes residual sugars, glycerol, and alcohol while producing acetaldehyde, which imparts the characteristic sharp, nutty, and saline flavors that define dry Sherries. This living organism requires specific conditions to thrive: consistent temperatures around 15-20°C, high humidity, and minimal disturbance. The flor’s metabolism also prevents oxidation, maintaining the wine’s pale color and fresh character. Beyond Sherry, similar biological aging occurs in Vin Jaune from France’s Jura region and some traditional wines from Hungary and Georgia. The flor’s activity varies seasonally, being most vigorous in spring and autumn, which influences the wine’s development throughout the aging process. This unique biological phenomenon represents one of wine’s most fascinating examples of beneficial microbial interaction.