Answered by Legionary of Christ Father Edward McNamara, professor of liturgy and dean of theology at the Regina Apostolorum university.
Q: In a January 10, 2017, article on “Reservation of Hosts” (https://zenit.org/articles/liturgy-q-a-reservation-of-hosts/), you say that “Such hosts, in accordance with liturgical Law, should be renewed every 15 days or so.” I cannot find a liturgical law stating this. Can you please direct me? I am trying to determine how often a host that is kept in a chapel for religious should be changed. I assume this would be the same for changing a host that is used for Eucharistic adoration. – J.D., Kansas City, Missouri
A: Effectively, the norm indicated here is a prudential one based on other laws and reasonable practice. There is no specific law mandating the time a host is to be changed.
For example, the norms for the reservation in the rites of “Holy Communion and Worship of the Eucharist Outside Mass” do not mandate a specific rhythm, saying only that:
“7. The consecrated hosts are to be frequently renewed and reserved in a ciborium or other vessel, in a number sufficient for the communion of the sick and others outside Mass.”
This norm is basically repeated in Canon 939:
“Consecrated hosts, in a quantity sufficient for the needs of the faithful, are to be kept in a pyx or ciborium, and are to be renewed frequently, the older hosts having been duly consumed.”
Canon 924 also throws light on the Church’s thinking:
“§1 The most holy Sacrifice of the Eucharist must be celebrated in bread, and in wine to which a small quantity of water is to be added.
“§2 The bread must be wheaten only, and recently made, so that there is no danger of corruption.
“§3 The wine must be natural, made from grapes of the vine, and not corrupt.”
The law on which this twice-monthly criterion is based is Canon 934 regarding the reservation of the Eucharist. This canon says that the Eucharist:
“1/ must be reserved in the cathedral church or its equivalent, in every parish church, and in a church or oratory connected to the house of a religious institute or society of apostolic life;
“2/ can be reserved in the chapel of the bishop and, with the permission of the local ordinary, in other churches, oratories, and chapels.
“§2. In sacred places where the Most Holy Eucharist is reserved, there must always be someone responsible for it and, insofar as possible, a priest is to celebrate Mass there at least twice a month.”
This final criterion regarding the celebration at least twice is probably motivated by two reasons.
First, it tries to ensure that the place of reservation is a true oratory, duly authorized by the bishop. The Eucharist may not be reserved in places where Mass cannot be celebrated, as this would sever the reservation from its ecclesial and liturgical context. This includes spaces reserved for prayer and meditation belonging to pious associations or informal houses of religious congregations.
It would not include special reservation or adoration chapels that are connected to larger churches where Mass is celebrated.
Second, the criterion of Mass twice a month acts as a guide of the frequency for renewal of the hosts, as such renewal would generally coincide with the said celebration. It would also naturally be the time to renew the host used for exposition.
In conclusion, the Church invites those responsible for the chapel to exercise great care in avoiding corruption of the sacred hosts. While the duration of a host may depend on climatic conditions, the twice-a-month rule covers most situations.
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