Historically, Vin Santo has been produced since the end of the Middle Ages. A legend from Siena mentions a friar who, in 1348, distributed a wine already used by his brothers to celebrate mass; the wine was known to heal the sick, hence the belief that it was a miraculous wine (“santo” meaning “holy”). That is not to negate the fact that the name “santo” derives from the fact that it has always been used in mass.
Traditionally, Vin Santo was produced by harvesting the best bunches (harvest “by choice”), which were then dried on mats or hung on hooks (traditionally the grapes were left when the moon was waning, with the belief that it would avoid rotting). Once dried, the grapes would be crushed (with or without the pulp depending on the tradition) and they would be transferred to wooden barrels of various sizes (generally between 15 to 50 litres), from which the previous year’s Vin Santo had recently been removed.