Bread have a special taste or texture. At one time, all yeast-leavened breads were sourdoughs. Recently there has been a revival of sourdough bread in artisan bakeries. Traditionally, peasant families throughout Europe baked on a fixed schedule, perhaps once a week. The starter was saved from the previous week's dough. The starter was mixed with the new ingredients, the dough was left to rise, and then a piece of it was saved (to be the starter for next week's bread). The rapid expansion of steam produced during baking leavens the bread, which is as simple as it is unpredictable. Steam-leavening is
Sacramental bread will bring out more clearly the force and importance of the sign of unity of all in the one bread, and of the sign of charity by the fact that the one bread is distributed among the brothers and sisters." In 1995 Joseph Cardinal Ratzinger, then Prefect of the Congregation for Divine Worship and the Discipline of the Sacraments, wrote a letter to the Episcopal Conferences in which he expanded the Code of Canon Law, stating that low-gluten bread would be considered “valid matter” for hosts as long as no additional substances “alter[ed] the nature of the substance of the