Jesus called the cup * the fruit of the vine* acknowledging that it was wine in the cup and that he was using a metaphor by calling it blood.
Since otherwise forcing His disciples to drink blood or tricking them into it, would have violated the Law that He Himself handed down at Mt. Sinai.
In fact, these are the very words used in the Canon of the Mass, for example, Eucharistic Prayer IV:
In a similar way, taking the chalice filled with the fruit of the vine, he gave thanks, and gave the chalice to his disciples, saying: TAKE THIS, ALL OF YOU, AND DRINK FROM IT: FOR THIS IS THE CHALICE OF MY BLOOD, THE BLOOD OF THE NEW AND ETERNAL COVENANT; WHICH WILL BE POURED OUT FOR YOU AND FOR MANY FOR THE FORGIVENESS OF SINS. DO THIS IN MEMORY OF ME.
Jesus and the Apostles certainly must have drunk of the other cups of Passover wine during the Last Supper, before the consecration of what He said is "the chalice of my Blood." It does not follow that he had partaken of the consecrated wine, His blood, which he gave his Apostles. The text doesn't say that.
This was His last meal before His death. The time would be short. This is why He said "But I say to you that I shall not drink again from this fruit of the vine until the day in which I shall drink it with you new in the Kingdom of my Father.”
This meal was His last drinking of the Passover wine before His death.