In at least some religious houses on December 27, the Feast of St. John, the religious superior blesses wine which is then drunk at the meal. The old Roman Ritual contained a blessing of wine for this feast. This commemorates the legend that once, while at Ephesus, John was given a cup of poisoned wine to drink. Before drinking, he blessed the cup and the poison departed the cup in the form of a serpent.
According to Francis X. Weiser in the Handbook of Christian Feasts and Customs (Harcourt Brace), as late as 1952 Catholics in Central Europe brought wine and cider to church for blessing on the feast of St. John. They then took it home and some of them poured a bit of the blessed wine or cider into every barrel in the cellar.
The blessed wine is called by some the "love of St. John." In some places the bride and groom at a wedding are given a sip to drink. In other cases a sip of the wine is given to a dying person as a sacramental.