During the Medieval Age, a soup was created using mutton stock as the base, to which various types of chopped up fruits were added. Plums, in the dried version of prunes, became the favored ingredient of this soup because of the flavor they imparted to the mix. Eventually the dish became known as Plum Soup. By the 16th century, the soup evolved into a pie with the addition of meat and suet, and baked within a pastry shell.
According to the Mother Goose's nursery rhyme: "Little Jack Horner sat in a corner, Eating his Christmas pie. He put in his thumb, and pull'd out a plum, And said 'What a good boy am I!'." It was the Plum Pie, descended from Plum Soup, that became the Christmas pie eaten by Little Jack Horner. Tradition claims that Plum Pie became associated with Christmas by being formed into a rectangular, rather than a round, shape to represent the manger-bed prepared for the Christ Child.
During the English Interregnum, while Oliver Cromwell was in power as Lord Protector, the Puritans frowned on any sort of extravagance. Unfortunately for Plum Pie, it was identified as one of those extravagances, and was outlawed throughout the British Isles and the British colonies in North America. In order to avoid trouble, but to still enjoy the dish, the people of England disguised it by forming it into a round ball and calling it minc'd pie. To 'mince' something means to crush or shred something. Beef suet was minced before adding it to this pie, and so the name would have been appropriate. Plums continued to provide the pie its distinctive flavor.
By the 1800s the name of the dish had been changed to Plum Pudding, being baked without the pastry shell. The dish has remained in that form to the present-day, and is uniquely associated with Christmas. To many people, myself included, plum pudding is the quintessential Christmas treat. I've never tried it, but I am sure that plum pudding made on July 4th would probably be bitter.
Now, most people today have no idea what is meant by the name 'beef suet' or why it was added to plum pudding. The suet is a fatty substance that surrounds a cow's kidneys. When the cow is butchered and cut up into pieces for human consumption, the fat surrounding the kidneys is sold as 'beef suet.' When steaming a pudding, the cook crumbles (crushes or shreds) the suet into tiny pieces to be mixed throughout the pudding batter. The purpose of using suet in the pudding is to create hundreds or even thousands of tiny air spaces throughout the dish. The suet melts late in the cooking process, after the starchy batter has begun to set, and therefore tiny spaces are left where the suet particles had been.
In order to make a proper plum pudding, actual beef suet is used, and the pudding must be steamed in boiling water for about four hours. Water must be continually added as it boils away, and therefore making a plum pudding using suet is not undertaken by most cooks. In recent years, a type of jelly or sauce, composed of diced apples mixed with various spices and marketed as 'mincemeat', has been substituted for the actual minced suet/meat. Although it reduces the baking time to about forty-five minutes, the product has a heavier texture.
Recipes for plum pudding varying from cook to cook. Some recipes call for every type of fruit available along with a couple spices, while others limit the variety of fruit to two or three mixed with seven or eight spices. Some recipes insist that only fresh fruit be used, while others call for glace fruit (which is candied fruit: diced and covered in concentrated sugar syrup). Regardless of the particular ingredients, most plum puddings contain diced nuts, especially almonds or walnuts, in addition to the fruit: hence the alternative name, fruit and nut cake.
Plum pudding, or Christmas pudding, contains a certain amount of alcohol, imparted by the ingredient of plum brandy. Any brandy will do, but plum brandy is the only one that would, of course, contribute to the 'plum' flavor of the dish. I guess you could leave the plums out, and add peach brandy to the mixture, but then the dish should bear the name: peach pudding, and it certainly would not be very 'traditional'. It should be noted also, that just prior to serving the dish, additional brandy should be spooned over the outside surface, which is then set afire so that a beautiful bluish haze envelopes the pudding.
While the traditional plum pudding, from the 17th Century onwards, was baked in a round bowl, giving the product a domed shape; the dish can be baked, like I do, in a bundt pan (sometimes referred to as an 'angel-food cake pan') or in any other baking dish.
And so now we come to the 10,000 pound elephant in the room. It has become very fashionable to dis (i.e. disparage) plum pudding, (or rather 'fruit cake' or 'fruit and nut cake') these days. Television personalities will not be caught dead claiming that they like the dish. And events are publicized in which 'fruit cakes' are loaded into catapults and trebuchets and launched hundreds of feet into fields by fanatics declaring that that is the only thing that can be done with them. Granted, the 'fruit and nut cakes' produced by commercial bakeries tend to be poor imitations of the original plum pudding; they sometimes are so dry and tasteless that they deserve to be destroyed.
Whether those fashionable people who zealously gloat about hating 'fruit cakes' have ever eaten real, homemade plum pudding is not known. I bet they, like myself, would come to love the dish. The surprise of biting into a fragment of walnut, followed by the sweet juiciness of biting into a piece of candied cherry, is something that makes Christmas: 'Christmas.'
