Should we use unleavened bread for communion?
Either leavened or unleavened bread is acceptable. This Holy Mystery, our statement about communion, says in the section on Communion Elements,
"It is appropriate that the bread eaten in Holy Communion both look and taste like bread. The use of a whole loaf best signifies the unity of the church as the body of Christ and, when it is broken and shared, our fellowship in that body (1 Corinthians 10:16-17).
Historical continuity with the practice of the universal church is important; however, worship planners should be sensitive to local situations. Bread may be made from any grain according to availability. In ecumenical and other settings, wafers may be an appropriate choice.
The loaf should be plain bread (no frostings, nuts, raisins, artificial coloring, or other additions). Leavened or unleavened bread is equally acceptable. In congregations where there are people with gluten allergies, gluten-free bread may be offered. The loaf broken at the table is to be the bread distributed to the people. As appropriate to the dignity of the occasion, care should be taken to avoid excessive crumbling of the bread and to remove large pieces that fall to the floor."
A Service Celebrating World Communion (Interpreter, October 2003) offers suggestions of breads from other traditions that might be used.