One of the movements of the offertory, after the gifts are brought to the altar, is that the deacon, or if there is no deacon the priest, pours a little water into the wine. St. Thomas Aquinas in his great “Summa Theologica” lists several reasons for this addition of water to the wine.
First, St. Thomas cites a custom for Jews at the time of Christ to slightly dilute the wine with water. Quite possibly, Jesus Himself followed this custom at the Last Supper. Since the Mass remembers the Last Supper, we include this detail of the ceremony with the Mass today.
Another reason for this movement is closely tied to the Passion of Jesus. In St. John’s Gospel, we read that when Jesus’ side is pierced with the soldier’s lance, both blood and water flowed symbolizing the sacraments of Eucharist and Baptism (John 19:34). If the wine is to become the Blood of Christ, then it’s appropriate that we put a bit of water with it as well to remember the blood and water that flowed from Christ’s side.
Finally, we include this addition of water and wine to symbolize our union with Christ. The wine to become the Blood of Christ is mixed with a bit of water, symbolizing we are part of His people. Thus Christ and His people are joined together in the one chalice.
Now that we understand this rite better, we can look more specifically at your question.
The General Instruction of the Roman Missal in #142 specifies that the wine and a bit of water is poured into the chalice, meaning the chalice that will be used by the priest. This chalice symbolizes the one cup that we are all to drink from (1 Corinthians 10:16-7). Even though there may be many chalices distributed at a Mass, they symbolize the one chalice we are drinking from together in coming into communion with Christ and one another.
Liturgists argue that this reading of #142 does not exclude the possibility of pouring a bit of water into the other chalices used at Mass. So it’s possible for a deacon or priest to use the practice as well.
Whichever way your deacon or priest handles it, remember that it’s their choice as the minister at that Mass. By seeing the deeper symbolism and meaning, we detect a value to help all of us to draw closer to Christ at this moment of preparation for the Liturgy of the Eucharist.
This column originally appeared in a previous edition of the St. Louis Review
Father Mayo is pastor of St. Raphael Parish in St. Louis