Why do Priests Pour Holy Water Into the Main Chalice Instead of Each Cup?

The easy answer to start off with is that the water that is used is not holy water. It is ordinary flat water from a bottle or a faucet.

During the offertory part of the mass (Which begins the Liturgy of the Eucharist) the priest pours just a few drops of water into the chalice and then says: “By the mystery of this water and wine may we come to share in the divinity of Christ who humbled himself to share in our humanity.”

This is done to symbolize the water and blood that flowed from the side of Christ on the cross (John 19:33) after he was pierced with the soldier’s lance. It calls our attention to the fact that what is human (our gifts of bread and wine) will become divine soon in the consecration.

The prescription for consecrated matter is bread and wine. The sacrament is valid even if water is not used at all but would be deemed illicit (e.g. the ritual not done correctly although the intention is real and therefore a valid sacramental presence). The General Instruction of the Roman Missal calls for a bit of water to be dropped into the priest’s chalice. We can infer a few things here:

1) The GIRM refers only to one chalice because at most masses there may only be one chalice and not many.

2) OR: The GIRM is calling attention to the ONE cup in which we all partake, meaning that we call attention to one consecrated cup in the Eucharistic Prayer because we all share in one cup, even though for the sake of allowing the blood of Christ to be available to all present we often use more than one container, all of those containers are considered ONE sacrament that we share together. This is more likely the intention and therefore the rubric calls for the priest to pour water into the cup that he will raise during consecration.

Now that said, there is not a prohibition against pouring water into other cups–but it can send a mixed message. All the chalices indeed contain the blood of Christ despite the lack of water in some, as the intention is to consecrate the wine and the ritual calls for us to simply be mindful of Christ’s sacrifice on the cross, by mingling the water into the wine.

So short answer is that the rubric only calls for water to be placed into the presider’s chalice.