Xynotyri is an unpasteurized whey cheese from Greece made from sheep's milk or goats milk, with a hard and flaky consistency, a pungent aroma and a yogurt-like sweet and sour taste. "Xynotyri" means "sour cheese" in Greek. Traditionally the cheese is drained and cured in reed baskets or allowed to mature in bags made of animal skin. Cow milk is not utilized in the production.

Xynotyri cheese can be consumed either as fresh cheese or after being ripened with the use of naturally dominating microflora during a 3-month month maturing period. The Lactobacillus strains in Xynotyri have antibacterial effects that kill Salmonella pathogens, a finding that is of special interest for producers of health-giving cheeses according to researchers at the French Institut National de la Santé et de la Recherche Médicale (INSERM).