Q. Jesus used bread and wine for the first Eucharist. When did the Church replace these with the Host?
A. The Church has never changed from using bread and wine as Jesus did. The Host is bread before it is consecrated to become Our Lord’s Body, even though it more closely resembles what has come in our time to be called a “wafer.” This bread is made simply of wheat flour and natural water that has been mixed and baked.
The first Eucharist, at which Our Lord Jesus presided, was a Passover meal. This means the bread He used was unleavened — that is, flat, without yeast to make it rise, like the matzoh used by observant Jews during Passover even today.
Given this precedent, Christians in the West have continued to use unleavened bread, though it has taken on various shapes, sizes, and thicknesses throughout the Church’s history. Some historical evidence suggests that as early as the sixth century, Hosts were being used that are as small and thin as they are now.
In the East, on the other hand, Christians have tended to use leavened bread, which in that regard looks more like the common bread we eat today.
As for wine: The priest does in fact still consecrate wine and consume Our Lord’s precious Blood at every Mass, even at those times when the cup is not shared with the others assembled. So the Church continues, as she always has, to consecrate bread and wine for the Eucharist.