At the conclusion of the Divine Liturgy on the Feast of the Transfiguration of our Lord on Mount Tabor, the priest blesses grapes. The blessing of grapes as well as other fruits and vegetables on this day is a beautiful sign of the final transfiguration of all things in Christ. It signifies the ultimate flowering and fruitfulness of all creation in the paradise of God’s unending Kingdom of Life where all will be transformed by the glory of the Lord. This is an ancient Christian custom. During the first week of August, farmers gathered the early fruits of their summer harvest (grapes, figs etc.) and presented them in the Church to be blessed and to give them freely to the congregation. These fruits are called the “beginnings”. In a text from the 7th century (“The Laws of the Kingdom” by emperor Constantine Porphyrogenitos) this custom is described vividly: “The Emperor of Constantinople gathers the Beginnings in Chalcedon, where there are many vines, and then he waits for the Patriarch of Constantinople to come on the the Feast of Transfiguration, to bless the fruits and to personally hand out the grapes to the people.” This is still the custom in many places in Greece where grapes are grown.
As grapes do not ripen at the same time everywhere, the Church adapted this tradition in various ways. In some places in the Holy Land, for instance, grapes are blessed on the feast of the prophet Elijah. In Russia, where grapes were not always readily available, apples were more commonly blessed, and Transfiguration is known as “Yablochny Spas“, “the Apple Feast of the Saviour”. In northern Russia, where even apples weren’t ripe by August 6/19, it was traditional to bless peas. Nowadays, when you can buy any sort of fruit or vegetable year round, we’ve lost the sense of getting a blessing to partake of the first fruits. But we can still try to keep to the spirit of this tradition. In our monastery we bless all sorts of fruit on Transfiguration, but we abstain only from grapes, taking care not to eat grapes of the new harvest until the feast, in keeping with the ancient monastic practise. — Mother Ephrosynia of the Lesna Convent in France
It is the tradition of the Day of Transfiguration to consecrate grapes, apples and other fruit after the Divine Liturgy. The custom of bringing fruit to the temple for consecration originates in the Old Testament time (Gen 4:2-4; Ex 13:12-13; Num 15:19-21; Deut 8:10-14). The Apostles brought this tradition to the Church of the New Testament (1 Cor 16:1-2). Instruction regarding bringing fruit to temple is found in the Third Rule of the Apostolic Canon, the earliest collection of ecclesiastic canons, known since the second century. In the first centuries of Christianity, the faithful brought forth to the temple the fruit and crops of the new harvest: bread, wine, oil, incense, wax, honey etc. From these offerings, bread, wine, incense, oil and wax were taken to the altar, while the rest was used for the needs of the clergy and the poor whom the church was caring for. These offerings were to express gratitude to God for all goods, but at the same time help servants of God and people in need. — Bishop Alexander (Mileant)