Bread unpredictable since the steam is not produced until the bread is baked. Steam leavening happens regardless of the raising agents (baking soda, yeast, baking powder, sour dough, beaten egg white) included in the mix. The leavening agent either contains air bubbles or generates carbon dioxide. The heat vaporises the water from the inner surface of the bubbles within the dough. The steam expands and makes the bread rise. This is the main factor in the rising of bread once it has been put in the oven. CO generation, on its own, is too small to account for the rise. Heat
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