20. [Christ] used bread, real bread for eating that was thin in shape and not thick, so that it was suitable for breaking into pieces (as was the custom of those people), and it was one whole. And moreover, the bread was unleavened or unfermented; of course, that was by accident and due to the circumstance of the law about the first day of unleavened bread; otherwise Christ would have used everyday bread. That is why Christ makes a comparison with everyday bread in John 6, and the apostle when speaking about the Supper mentions simply the bread as it was used in Corinth, because unleavened bread had been abolished along with the Passover Lamb and the other ceremonies. Otherwise, this would be a matter of indifference, provided there is no belief of necessity. And therefore, the debate between the Greeks and Latins over this matter is an idle one.
21. In the same way he used the drink of the produce or fruit of the vine, i.e., wine (Matt 26:29). But it is not known whether the wine was red as it nearly always is in that region (Prov 21:31) and wherefore it is also called the “blood of grapes” (Gen 49:11), or whether it was diluted (which is called mixed wine), in keeping with the custom of blending the wine in those warmer climates (Prov 9:2, 5 and 23:30). Justin states that a cup of wine diluted with water was used. But that adds nothing to the religious character and mystery; nor does the material and shape of the cup (i.e., the chalice), whether it is wooden, silver, or gilded.
22. And the fact that for the mysteries he chose bread and wine, common things taken from everyday life, is because of the very close similarity and analogy in the properties and effects of both (i.e., as basis and very necessary nourishment) to the things they signify: the body and blood of the Lord.
23. Hence the papal teachers and otherws who follow them do not sin lightly when they use bread that is not bread but little slices of the smallest size and then as a shadow, quite unlike the looks of real bread (and not worthy of that name) and not having the energy to nourish; they are wafers, or offerings as they call them. And they also use unleavened bread, as if it is necessary for the sacrament because of the precedent of Christ. And what is more, for the sake of mystery they use diluted wine, over which some ancients like Cyprian and others have philosophized in too much detail and dilutedly.
24. But if [the sacrament is held] where bread and wine are not used, or where they cannot be obtained in abundance, it is possible to use whatever takes the place of bread and wine, or whatever is the equivalent for those people.
Disputation 45, “On the Lord’s Supper,” in Synopsis of a Purer Theology, 584-585.