The churches have declared their judgments concerning the use of real wine in the Lord’s Supper. 

The careful reader will note that the following confessional, catechetical and historical documents do not avoid the issue of wine in the Lord’s Supper by using such terms as “the cup,” which some people might consider a safe alternative, while still using biblical terminology; rather, while not avoiding the word “cup,” they also use the unambiguous and specific term, “wine.” In some cases, these confessional documents use the words “cup” and “wine” interchangeably, which clearly reflects their understanding that the communion cup contains wine. (Hereafter, the author has used bold typeface wherever the word “wine” appears, so that readers of this page can find the word more easily.)

Westminster Confession of Faith, Chapter XXIX, iii 

The Lord Jesus has, in this ordinance, appointed His ministers to declare His word of institution to the people, to pray, and bless the elements of bread and wine, and thereby to set them apart from a common to an holy use; and to take and break the bread, to take the cup, and (they communicating also themselves) to give both to the communicants; but to none who are not then present in the congregation. 

Westminster Larger Catechism Q. 168 

What is the Lord’s supper? A. The Lord’s supper is a sacrament of the New Testament, wherein, by giving and receiving bread and wine according to the appointment of Jesus Christ, his death is showed forth; and they that worthily communicate feed upon his body and blood, to their spiritual nourishment and growth in grace; have their union and communion with him confirmed; testify and renew their thankfulness, and engagement to God, and their mutual love and fellowship each with the other, as members of the same mystical body.  

Westminster Larger Catechism Q. 169 

How hath Christ appointed bread and wine to be given and received in the sacrament of the Lord’s supper? A. Christ hath appointed the ministers of his Word, in the administration of this sacrament of the Lord’s supper, to set apart the bread and wine from common use, by the word of institution, thanksgiving, and prayer; to take and break the bread, and to give both the bread and the wine to the communicants: who are, by the same appointment, to take and eat the bread, and to drink the wine, in thankful remembrance that the body of Christ was broken and given, and his blood shed, for them. 

Westminster Larger Catechism Q. 177

Wherein do the sacraments of baptism and the Lord’s supper differ?  A. The sacraments of baptism and the Lord’s supper differ, in that baptism is to be administered but once, with water, to be a sign and seal of our regeneration and ingrafting into Christ, and that even to infants; whereas the Lord’s supper is to be administered often, in the elements of bread and wine, to represent and exhibit Christ as spiritual nourishment to the soul, and to confirm our continuance and growth in him, and that only to such as are of years and ability to examine themselves.

Westminster Shorter Catechism Q. 96. 

What is the Lord’s Supper? A. The Lord’s Supper is a sacrament, wherein, by giving and receiving bread and wine, according to Christ’s appointment, his death is showed forth; and the worthy receivers are, not after a corporal and carnal manner, but by faith, made partakers of his body and blood, with all his benefits, to their spiritual nourishment, and growth in grace.  

The [Westminster] Directory for the Publick Worship of God (1645) 

OF THE CELEBRATION OF THE COMMUNION, OR SACRAMENT OF THE LORD'S SUPPER. 

After this exhortation, warning, and invitation, the table being before decently covered, and so conveniently placed, that the communicants may orderly sit about it, or at it, the minister is to begin the action with sanctifying and blessing the elements of bread and wine set before him, (the bread in comely and convenient vessels, so prepared, that, being broken by him, and given, it may be distributed amongst the communicants; the wine also in large cups,) having first, in a few words, shewed that those elements, otherwise common, are now set apart and sanctified to this holy use, by the word of institution and prayer.  

The [RPCNA] Directory for the Worship of God (1945) 

The form to be used is: “Bless so much of the elements of bread and wine as shall be used on this occasion, which we hereby set apart from a common to a sacramental use, in the name and by the authority of the Lord Jesus Christ, the King and Head of the Church.”  

The Heidelberg Catechism Question 78. 

Do then the bread and wine become the very body and blood of Christ? Answer: Not at all: but as the water in baptism is not changed into the blood of Christ, neither is the washing away of sin itself, being only the sign and confirmation thereof appointed of God; so the bread in the Lord's supper is not changed into the very body of Christ; though agreeably to the nature and properties of sacraments, it is called the body of Christ Jesus.  

The Belgic Confession, Article 35: The Sacrament of the Lord’s Supper 

To represent to us this spiritual and heavenly bread Christ has instituted an earthly and visible bread as the sacrament of his body and wine as the sacrament of his blood.  

The Scottish Confession of Faith (1560) Chapter 22. Of the Right Administration of the Sacraments 

For Christ Jesus said, Take, eat, etc. Do ye this in remembrance of me.  By which words and charge he sanctified bread and wine, to be the sacrament of his body and blood, to the end that the one should be eaten, and that all should drink of the other; and not that they should be kept to be worshipped, and honoured as God, as the blind Papists have done heretofore, who also committed sacrilege, stealing from the people the one part of the sacrament: to wit, the blessed cup.  

The Thirty-Nine Articles (1562, Modernized) XXVIII. 

Of the Lord's Supper Transubstantiation (or the change of the substance of Bread and Wine) in the Supper of the Lord, cannot be proved by holy Writ; but is repugnant to the plain words of Scripture, overthroweth the nature of a Sacrament, and hath given occasion to many superstitions. 

Some people, eager to avoid the force of the above, have suggested that the English word “wine” is a generic term, meaning both the fermented juice of grapes, but also unfermented juice. In response, we invite the reader to consider the definition of “wine” as listed in a few reliable dictionaries. The reader will soon discover that “wine,” as used in the above confessional and historical documents, can only mean “the fermented juice of grapes.” 

Some readers will be especially interested in the first example, because it is a citation from the dictionary by Samuel Johnson. Since it dates from the mid-eighteenth century, it is not affected by any bias from the twentieth century.

Readers who want to delve even deeper into the meaning of the English word "wine," especially as it is used in the Westminster Confession of Faith, might want to study how the word "wine" is used in the King James Version of the Bible. The King James Version was published in 1611, and so the translators of the King James Version moved in the same world of ideas as the Westminster Assembly. 

A DICTIONARY OF THE ENGLISH LANGUAGE
in which the words are deduced from their originals,  and illustrated in their different significations by examples from the best writers.

by Samuel Johnson, The Sixth Edition, published in 1766, Volume 2, Page 1068 https://archive.org/stream/dictionaryofengl02johnuoft#page/n1067/mode/2up 

WINE n. 

1. The fermented juice of the grape. 

[Below this definition, Johnson then cites examples of this use of the word “wine” in Shakespeare, the Bible, Bacon, Sandys, Milton, Pope, Herbert, and Swift; these examples are omitted here for the sake of brevity.] 

2. Preparations of vegetables by fermentation called by the general name of wines; have quite different qualities from the plant; for no fruit, taken crude, has the intoxicating quality of wine. 

Arbuthnot

American Dictionary of the English Language by Noah Webster (1828)

http://www.webstersdictionary1828.com/Dictionary/wine

WINE, noun [Gr.]

1. The fermented juice of grapes; as the wine of the Madeira grape; the wine of Burgundy or Oporto.

2. The juice of certain fruits, prepared with sugar, spirits, etc.; as currant wine; gooseberry wine

3. Intoxication. 

Noah awoke from his wine Genesis 9:21.

4. Drinking.

They that tarry long at the wine Proverbs 23:30.

Corn and wine in Scripture, are put for all kinds of necessaries for subsistence. Psalm.

Bread and wine in the Lords supper, are symbols of the body and blood of Christ. 

Webster’s New Twentieth Century Dictionary of the English Language, Unabridged
Wine, n. [ME. win; AS. Win, from L. vinum, wine.] 

1. the fermented juice of grapes, used as an alcoholic beverage and in cooking, religious ceremonies, etc.; wines vary as to color (red or white) and sugar content (sweet or dry), may be effervescent (sparkling) or non-effervescent (still), and are sometimes strengthened with additional alcohol (fortified). 

2. the fermented juice of other fruits or plants, used as a beverage; as dandelion wine. 

3. intoxication, as from wine. Noah awoke from his wine. --Gen.ix.24. 

4. a wine party; specifically, at an English university.[Brit.] 

5. a dark, purplish red resembling the color of red wines. 

6. In pharmacy, a medicinal solution in which wine is the solvent. 

Birch wine; see under birch. 

Heavy oil of wine; see ethereal oil of wine, under ethereal. 

New wine in old bottles; something new that is too potent to be confined in old bottles; something new that is too potent to be confined in old forms: see Matt. ix. 17. 

Spirit of wine; alcohol. 

To drink wine ape; to drink enough wine to make one silly. [Obs.]     

Oxford Online Dictionary

https://en.oxforddictionaries.com/definition/us/wine
Wine1
NOUN 

1. An alcoholic drink made from fermented grape juice. 

‘he opened a bottle of red wine’ 

‘the regional foods and wines of France’
1.1 [with modifier] An alcoholic drink made from the fermented juice of specified other fruits or plants 

‘a glass of elderflower wine’
1.2 short for wine red