Note: We are indebted to St. Vladimir seminarian and former St. Katherine of Sinai novice Vasili Bassakyros for telling us about this old and venerable tradition, which he learned during his time on Mt. Sinai and continues at home parish of Three Hierarchs in Brooklyn, NY.
At the close of every monastery meal, the priest vests in his exorassa and stole. He lights a small hand censor (not one with chains, but the type that sits or it held by a handle as we use at home) and places incense in it. Then he pours wine into a small bowl and places it on a tray with pieces of prosphora blessed at the liturgy. The monks rise from their seats and begin to sing the troparion of the day. While another monk holds the censor and walks behind the priest, the priest offers the tray to the brethren. Each monk takes one piece of bread in his right hand and dips it in the wine. As the priest passes, the monk with the censor approaches, and the monk then makes the sign of the cross over the censor and eats the bread. Then the priest says the benediction and the monks go to their obediances.
According to the brethren of Mt. Sinai, this is the original form of communion, taking its place at the end of the "Agape meal." While the Eucharist practice we have now continued to develop within the Liturgy, the monks never gave up the practice of what later became known as ipsoma. Their only modification was drop the consecration prayers over the bread and wine. The wine is not blessed, and the bread used is blessed like antidoron. Never are the actual Body and Blood ever used in this rite.
Ipsomata are distributed to faithful members whose nameday is being celebrated at a Divine Liturgy. Each ipsomata is a cube of blessed bread, dipped in wine and divided into four pieces. A piece is eaten every morning (before breakfast) for four days (or three if the first is eaten immediately after Communion).