Assuming the priest is aware of it, but doesn’t know which hosts are consecrated and which are not, then what he will have to do is place the ciborium on the corporal and simply intend to consecrate any hosts that are not consecrated. There’s nothing conditional wrong about it. Any hosts already consecrated are unaffected, and the unconsecrated hosts consecrated.
If you are a priest, then surely you know that you are speaking to one of two methods. If you prefer this method, that is your prerogative. I do not do the absolute consecration as you describe. I was formed in a different way, which is what I taught to my own students and the same formula I consistently apply when I have to confer other sacraments conditionally; I am always therefore following the same pattern for intellectual consistency…also because one is labouring under duress in these moments of ordeal.
I think Fr. Ruggero probably knows more about that than most of us do!
When I was teaching liturgy and sacraments at this level…what to do when something catastrophic happens…I was not teaching in English. The basis for the documentation I was lecturing from rested with a body of literature and instructions I had gathered; the foundation for which was,
De defecticus, which I supplemented with similar documents from other sources.
To keep this simple, one of the best books in English is by Father Nicholas Halligan, OP. He is quite solid as a sacramental theologian. It is entitled “The Sacraments and their Celebration”. It was originally published in the United States by Alba House and collects together a number of the issues I lectured on. I knew Father Halligan personally and held him in high regard.
These are not stories I like to tell outside of the classroom as it involves resolution to liturgical crises that really do not need to be in popular conversations. In this case I will relate Father’s answer, which is substantially my own.
This is from page 70:
If consecrated hosts should become mixed with unconsecrated ones, the priest should consecrate the latter at a subsequent Mass and before being distributed to the faithful, either by consecrating the whole amount conditionally or absolutely only those not consecrated. The same procedure is to be followed is a quantity of unconsecrated wine is added to render the Real Presence doubtful.
By God’s grace, this only happened to me, in my own experience, one time; it was at a parish I was visiting.
There was confusion as several were trying to prepare the sacred vessels, such that unconsecrated hosts were placed in the ciborium that was normally in the tabernacle but brought out momentarily for the purpose of assessing how many hosts were consecrated.
There was a luna in the tabernacle, assuring the Real Presence; the tabernacle could remain closed and people genuflect to it. I discreetly transferred the ciborium in question to a place of safekeeping that I could easily access but told no one to touch…and, during the offertory, I myself transferred it nonchalantly to the altar as the server brought forward the missal, chalice, cruets, and other items.
As we proceeded to the anaphora (Eucharistic Prayer), in every way I had a normal intention relative to the paten of my chalice, the contents of my chalice and a dish with hosts for communion at this Mass and the cups for the faithful receiving the Precious Blood.
For the one ciborium, with a mix of consecrated and unconsecrated hosts, I attenuated the intention it is regard and consecrated its contents
sub condicione. In other words, intending that what was in it that was in fact consecrated was unaffected – but that what was in it and was NOT consecrated would be, by the epiclesis and the words of the initiative narrative, positively and definitively consecrated.
In sacramental theology, it would be a sin (and wholly inappropriate) to attempt to effect a sacramental reality that already exists. Thus it would be wrong to absolutely consecrate the entiety of the ciborium’s content. Using the conditional removes the contentious point.
This was all accomplished at the first possible interest, an hour after the unfortunate mistake that was caused by a chain of confusion and a momentary lapse by a well-intenioned person. Happily resolved in short order, it was a teaching moment for everyone with better protocols for how things were done going forward.
The alternate thesis is to absolutely consecrate what is not consecrated in the ciborium. The priest may certainly choose that option but I prefer to go, in all cases, where I have doubt by using the conditional formulation. It is not only how I was schooled academically, it was how I was trained pastorally.
The greatest care should be taken by everyone concerned so that something like this does not happen. Keeping the consecrated hosts exclusively in the tabernacle and the unconsecrated hosts exclusively in the sacristy go far to obviating confusion.