Matzo must be ground from one of the five grains specified in Jewish law for Passover matzo: wheat, barley, spelt, rye or oat. Per Ashkenazic tradition, matzo made with wine, fruit juice, onion, garlic, etc., is not acceptable for use at any time during the Passover festival except by the elderly or unwell. Matzo dough is quickly mixed and rolled out without an autolyse step as used for leavened breads. Most forms are pricked with a fork or a similar tool to keep the finished product from puffing up, and the resulting flat piece of dough is cooked at high temperature
Matzo for the Eucharist are flat, unleavened bread. The main reason for the use of this bread is the belief, that because the last supper was described in the Synoptic Gospels as a passover meal, the unleavened matzo bread was used by Jesus when he held it up and said "this is my body". All Byzantine Rite churches use leavened bread for the Eucharist as this symbolizes the risen Christ. Some Oriental Orthodox and Eastern Catholic Christians use leavened bread, as in the east there is the tradition, based upon the gospel of John, that leavened bread was on the table