I didn’t seem to get an answer from the Orthodox here on whether the bread and wine remain after consecration, but I tend to agree with
stephraim posting before me. With regard to the Eucharist, the teachings of Catholics and Orthodox are virtually identical even though there are a number of modern Orthodox who are adverse to the term
Transubstantiation.
I did a little homework, however, and I thought I would share: I mentioned earlier that I know of 3 Orthodox Catechisms that use the term “Transubstantiation” to describe the Eucharist. The one goes back to 1645 (or 1640) or so in the writing of Peter Mohyla, Metropolitan of Kiev.
Here are some other Orthodox sources using the term
Transubstantiation:*
Orthodox Wiki
“Other areas of agreement between Greek Orthodoxy and the AOC included common acceptance of the dogmatic decisions of the seven Ecumenical Councils, the seven Sacraments, the original form of the Nicene Creed, the concept of
transubstantiation, the declaration of the Virgin Mary as Mother of God, justification by both faith and good works, and the rejection of predestination.”
The Confession of Dositheus (6.17e, 6.17h) (aka Acts and Decrees of the Synod of Jerusalem, A.D. 1672)
"So that though there may be many celebrations in the world at one and the same hour, there are not many Christs, or Bodies of Christ, but it is one and the same Christ that is truly and really present; and His one Body and His Blood is in all the several Churches of the Faithful; and this not because the Body of the Lord that is in the Heavens descendeth upon the Altars; but because the bread of the Prothesis set forth in all the several Churches, being changed and
transubstantiated, becometh, and is, after consecration, one and the same with That in the Heavens. For it is one Body of the Lord in many places, and not many; and therefore this Mystery is the greatest, and is spoken of as wonderful, and comprehensible by faith only, and not by the sophistries of man’s wisdom; whose vain and foolish curiosity in divine things our pious and God-delivered religion rejecteth. … “Further,
we believe that by the word “transubstantiation” the manner is not explained, by which the bread and wine are changed into the Body and Blood of the Lord, — for that is altogether incomprehensible and impossible, except by God Himself, and those who imagine to do so are involved in ignorance and impiety, — but that the bread and the wine are after the consecration, not typically, nor figuratively, nor by superabundant grace, nor by the communication or the presence of the Divinity alone of the Only-begotten, transmuted into the Body and Blood of the Lord; neither is any accident of the bread, or of the wine, by any conversion or alteration, changed into any accident of the Body and Blood of Christ,
but truly, and really, and substantially, doth the bread become the true Body Itself of the Lord, and the wine the Blood Itself of the Lord, as is said above. Further, that this Mystery of the Sacred Eucharist can be performed by none other, except only by an Orthodox Priest, who hath received his priesthood from an Orthodox and Canonical Bishop, in accordance with the teaching of the Eastern Church. This is compendiously the doctrine, and true confession, and most ancient tradition of the Catholic Church concerning this Mystery; which must not be departed from in any way by such as would be Orthodox, and who reject the novelties and profane vanities of heretics; but necessarily the tradition of the institution must be kept whole and unimpaired. For those that transgress the Catholic Church of Christ rejecteth and anathematiseth.”
Council of Constantinople 1727
“As an explanatory and most accurately significant declaration of this change of the bread and the wine into the body of the Lord itself and His blood the faithful ought to acknowledge and receive the word
transubstantiation, which the Catholic Church as a whole has used and receives as the most fitting statement of this mystery. Moreover they ought to reject the use of unleavened bread as an innovation of late date, and to receive the holy rite in leavened bread, as had been the custom from the first in the Catholic Church of Christ.”
There are at least a couple 15th-16th century Orthodox bishops,
Gennadius and Gabriel Severus, who also used the term Transubstantiation to describe the Eucharist.*