re: #473 reine.de.tout
From Redemptionis Sacramentum:
[48.] The bread used in the celebration of the Most Holy Eucharistic Sacrifice must be unleavened, purely of wheat, and recently made so that there is no danger of decomposition. It follows therefore that bread made from another substance, even if it is grain, or if it is mixed with another substance different from wheat to such an extent that it would not commonly be considered wheat bread, does not constitute valid matter for confecting the Sacrifice and the Eucharistic Sacrament. It is a grave abuse to introduce other substances, such as fruit or sugar or honey, into the bread for confecting the Eucharist. Hosts should obviously be made by those who are not only distinguished by their integrity, but also skilled in making them and furnished with suitable tools.
Mom’s ciabatta, of course, can be consumed in vast quantities after the Mass.