Posset was originally a thick drink served hot.
Now, it is a thick, flavoured cream served as a dessert, and served chilled.
It used to be made from boiled milk, with some alcohol in it such as beer or wine to curdle it, and some sugar perhaps, thickened with bread. Consequently, it was relatively thin. Now, in our more affluent times, it is usually made thick enough that you need to eat it with a spoon, and made entirely with heavy cream, and no other thickener.
Posset was very popular in the Middle Ages; bread used as a thickener is a sign of a recipe hearkening back to this time.
The plainer versions of the drinkable ones came to be regarded as food for invalids, while the richer ones with cream, sugar and spices and or herbs were good enough for the formal dinners of the aristocrats. Later on, theirs became an even richer dish, drawing on cream. Ordinary people would not have been able to afford the cream and spices.
Posset sets were made by china makers or silver makers. There would be a container to make it in, as well as a cup to serve it in, spoons, and various other small dishes.
Literature & Lore
“A Plain Ordinary Posset: Put a pint of good Milk to boil; as soon as it doth so, take it from the fire, to let the great heat of it cool a little; for doing so, the curd will be the tenderer, and the whole of a more uniform consistence. When it is prettily cooled, pour it into your pot, wherein is about two spoonfuls of Sack and four of Ale, with sufficient Sugar dissolved in them. So let it stand a while near the fire, till you eat it.” — from “The Closet of the Eminently Learned Sir Kenelm Digby, Knight, Opened” (ca 1669).
“…for supper, we often give the harvest-men a posset crum’d with bread, made in this plain manner: The maid-servant boils new milk, and when it is so done, she puts about a pint of it into each man’s wooden dish, and immediately adds a quarter of a pint of stale strong beer, some coarse sugar and crumbled bread, which turns the milk into a posset, and gives the men a palatable supper; but if our country housewife has a mind to make a better posset she may:–Take a quart of new milk, and mix it with a pint of ale, the yolks of eight eggs, and the whites of four, which when beaten must be put in the milk and ale; then add some sugar and nutmeg, and stir it all the while it is on the fire till it is thick (but it must not boil) and it’s done for eating; but if you will have the posset richer, use cream instead of milk. Or to make a sack-posset:–Take a quart of milk or cream, boil it with sugar, mace, and nutmeg; then take half a pint of sack, and half a pint of ale, and boil these well together with sugar; then put your milk or cream to your sack and ale in a bason, cover it with a hot dish, and set it two or three hours by a fire before you eat it. Or you may bake a sack-posset thus:–Beat eight eggs, and strain them into a quart of milk or cream, season them with nutmeg and sugar, then put to them a pint of sack, stir them together and put them into a bason, and set it in the oven no hotter than for a custard; let it stand two hours.–Or, grate three penny Naples-biskets, and boil them with nutmeg and sugar in a quart of milk or cream; then warm a pint of sack and put it into a bason, and on that pour your boiled cream by a high fall, when after a little time standing it may be eaten. But for an ordinary sack-posset–Sir Kenelm Digby says, boil a pint of milk, and as soon as it boils take it off, and let it cool a little, for by so doing, says he, the curd will be the tenderer; then pour it into a pot, wherein are two spoonfuls of sack and four of ale, sugar it, and let it stand by a fire-side till you eat it.” — William Ellis. The Country Housewife’s Family Companion. James Hodges, London and B. Collins, Salisbury. 1750.
“Ale Posset: Take a small piece of white bread, put it into a pint of milk and set it over the fire. Then put some nutmeg and sugar into a pint of ale, warm it, and when the milk boils pour it upon the ale. Let it stand a few minutes to clear.” — Henry Hartshorne. The Household Cyclopedia. New York: Thomas Kelly. 1881.
“To make the Pope’s Posset: — Blanch and beat three-quarters of a pound of almonds so fine, that they will spread between your fingers like butter, put in water as you beat them to keep them from oiling; then take a pint of sack or sherry, and sweeten it very well with double-refin’d sugar, make it boiling hot, and at the same time put half a pint of water to your almonds, and make them boil; then take both off the fire, and mix them very well together with a spoon; serve it in a china dish.” — William Carew Hazlitt (1834 to 1913). Old Cookery Books and Ancient Cuisine. London: The Book-Lover’s Library. 1902.
Some think the word “Posset” might come from the Latin noun “posca”, a drink with vinegar in it.