Posset
A posset (also spelled poshote, poshotte) was a British hot drink of milk curdled with wine or ale, often spiced, which was popular from medieval times to the 19th century. The word is mainly used nowadays for a related dessert similar to syllabub. In the Middle Ages, it was used as a cold and flu remedy and was more of a drink than a mousse.
Introduction
To make the drink, milk was heated to a boil, then mixed with wine or ale, which curdled it, and the mixture was usually spiced with nutmeg and cinnamon.
It was considered a specific remedy for some minor illnesses, such as a cold, and a general remedy for others, as even today people drink hot milk to help them get to sleep.
History
The OED traces the word to the 15th century: various Latin vocabularies translate balducta, bedulta, or casius as "poshet", "poshoote", "possyt", or "possot". Russell's Boke of Nurture (c. 1460) lists various dishes and ingredients that "close a mannes stomak", including "þe possate". Posset is frequently used as a starting point for other recipes (e.g. "Make a styf Poshote of Milke an Ale", and "Take cowe Mylke, & set it ouer þe fyre, & þrow þer-on Saunderys, & make a styf poshotte of Ale", each of which is the first sentence of a longer recipe). Recipes for it appear in other 15th-century sources: boil milk, add either wine or ale "and no salt", let it cool, gather the curds and discard the whey, and season with ginger, sugar, and possibly "sweet wine" and candied anise.