The Eastern Orthodox Church continues the ancient practice of using leavened bread for the Eucharist. Thus, the sacramental bread symbolizes the Resurrected Christ. The sacramental bread, known as prosphora, may be made out of only four ingredients:
Sometimes, holy water will be either sprinkled into the dough or on the kneading trough at the beginning of the process.
The baking may only be performed by a believing Orthodox Christian in good standing—having preferably been recently to Confession, and is accompanied by prayer and fasting. Before baking, each loaf is formed by placing two disks of dough, one on top of the other, and stamping it with a special liturgical seal. The prosphora should be fresh and not stale or moldy when presented at the altar for use in the Divine Liturgy. Often several prosphora will be baked and the priest shall choose the best one for the Lamb (Host) that will be consecrated.
The word host is derived from the Latin, hostia, which means "victim" or "sacrificial animal". The term can be used to describe the bread both before and after consecration, though it is more correct to use it after consecration - "altar bread" being preferred before consecration. Western theology teaches that at the Words of Institution the bread is changed (transubstantiated into the Body of Christ, while Eastern theology sees the epiclesis as no less necessary.
Hosts are often made by nuns as a means of supporting their religious communities. In the Latin Rite, unleavened bread is used as in the Jewish Passover or Feast of Unleavened Bread. The Byzantine Rite Eastern Catholic Churches (like the Eastern Orthodox Church) use leavened bread for Prosphora (the Greek word for Eucharistic altar bread). The Armenian Catholic Church (like the Armenian Apostolic Church), the Syro-Malabar Church and the Maronite Church have adopted the use of unleavened bread (see liturgical latinisation). Some traditions proscribe the use of spiced, flavored or sweetened hosts, while others allow it. However, both Eastern and Western traditions insist that the bread must be made from wheat. The Code of Canon Law, Canon 924 requires that the hosts be made from wheat flour and water only.
The General Instruction of the Roman Missal §321 recommends that "the eucharistic bread ... be made in such a way that the priest at Mass with a congregation is able in practice to break it into parts for distribution to at least some of the faithful. ... The action of the fraction or breaking of bread, which gave its name to the Eucharist in apostolic times, 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."