By Robert Chambers
This is an excerpt from Chambers’ work The Book of Days: A Miscellany of Popular Antiquities in Connection with the Calendar, Including Anecdote, Biography, & History, Curiosities of Literature and Oddities of Human Life and Character, Volume 2. (1864). This book and its excerpt are in the public domain. We have added some annotations, links, and images and performed some slight editing.
Twelfth-day Eve is a rustic festival in England. Persons engaged in rural employments are, or have heretofore been accustomed to celebrate it; and the purpose appears to be to secure a blessing for the fruits of the earth. 
In Herefordshire, at the approach of the evening, the farmers with their friends and servants meet together, and about six o’clock walk out to a field where wheat is growing. In the highest part of the ground, twelve small fires, and one large one, are lighted up. The attendants, headed by the master of the family, pledge the company when in old cider, which circulates freely on these occasions. A circle is formed round the large fire, when a general shout and hallooing takes place, which you hear answered from all the adjacent villages and fields. Sometimes fifty or sixty of these fires may be all seen at once. This being finished, the company return home, where the good housewife and her maids are preparing a good supper. A large cake is always provided, with a hole in the middle. 
After supper, the company all attend the bailiff (or head of the oxen) to the wain-house,  where the following particulars are observed: The master, at the head of his friends, fills the cup (generally of strong ale), and stands opposite the first or finest of the oxen. He then pledges him in a curious toast: the company follow his example, with all the other oxen, and addressing each by his name. This being finished, the large cake is produced, and, with much ceremony, put on the horn of the first ox, through the hole above mentioned. The ox is then tickled, to make him toss his head: if he throw the cake behind, then it is the mistress’s perquisite; if before (in what is termed the boosy), the bailiff himself claims the prize. The company then return to the house, the doors of which they find locked, nor will they be opened till some joyous songs are sung. On their gaining admittance, a scene of mirth and jollity ensues, which lasts the greatest part of the night.’ — Gentleman’s Magazine, February, 1791. The custom is called in Herefordshire Wassailing. The fires are de-signed to represent the Saviour and his apostles, and it was customary as to one of them, held as representing Judas Iscariot, to allow it to burn a while, and then put it out and kick about the materials.
At Pauntley, in Gloucestershire, the custom has in view the prevention of the smut in wheat. ‘All the servants of every farmer assemble in one of the fields that has been sown with wheat. At the end of twelve lands, they make twelve fires in a row with straw; around one of which, made larger than the rest, they drink a cheerful glass of cider to their master’s health, and success to the future harvest; then returning home, they feast on cakes made with carraways, soaked in cider, which they claim as a reward for their past labour in sowing the grain.’
‘In the south hams [villages] of Devonshire, on the eve of the Epiphany, the farmer, attended by his workmen, with a large pitcher of cider, goes to the orchard, and there encircling one of the best bearing trees, they drink the following toast three several times:
Here’s to thee, old apple-tree,
Whence thou mayst bud,
and whence thou mayst blow!
And whence thou mayst bear apples enow!
Hats full! caps full!
And my pockets full too! Huzza!
This done, they return to the house, the doors of which they are sure to find bolted by the females, who, be the weather what it may, are inexorable to all entreaties to open them till some one has guessed at what is on the spit, which is generally some nice little thing, difficult to be hit on, and is the reward of him who first names it. The doors are then thrown open, and the lucky clod-pole receives the tit-bit as his recompense. Some are so superstitious as to believe, that if they neglect this custom, the trees will bear no apples that year.’ — Gentleman’s Magazine, 1791, p. 403. 
This excerpt was adapted from the very excellent Hillman’s Hyperlinked and Searchable Chambers’ Book of Days. (Here)
- Twelve day eve is also variously known as Twelfth Night and Epiphany Eve and has historically been celebrated on January 5 or January 6. In some parts of cider-making England, it can also be celebrated on “Old Twelvey,” the 17th of January. (The 6th of January as Epiphany Eve only dating to the 1752 switch to the Gregorian calendar. Old habits die hard or hardly die.)
- King cakes for Twelfth Night are a common way to celebrate and can be served throughout the period leading up to Lent. They are also known as three kings’ cake, galette des rois or gâteau de roi (France), Koningentaart (Belgium, Netherlands), Bolo-rei (Portugal), Roscón de Reyes (Spain) and Rosca de Reyes (Latin America).
- Wagon house: a house or shed for wagons and carts.
- For more on this tradition, see “Wassail! The pagan origins of a Yuletide cider festival.”
”Distinctive Traditions of Epiphany” (Baylor University)
“Epiphany” (Wikipedia) lists other customs such as chalking the door and winter swimming.
“Let Them Eat Twelfth Night Cake or King Cake on 12th Day of Christmas” (Racing Nellie Bly)
“Twelfth Cake” (Foods of England)