This recipe is based on a recipe mentioned in Pliny the Elder’s Natural History Book 15, Chapter 17:
e pomis proprietas piris quae vini, similiterque in aegris medentes cavent. e vino et aqua cocuntur atque pulmentari vicem inplent, quod non alia praeter cotonea ac struthea.
Of all the apple kind pears have the quality of wines, and like wine they are avoided by doctors in the treatment of the sick. Boiled in wine and water they make a sort of jam, as does no other fruit except the quince and the sparrow-apple.
Latin text and English translation from Pliny, H. Rackham, W. H. S. Jones, and D. E. Eichholz. 1960. Pliny: Natural history. Loeb Classical Library, Harvard University Press, Volume IV.
Although in Grant’s book it is described as Pear Jelly, when I made it, it was liquidy, more like Pear Sauce. Note that the alcohol from the wine does not cook off, so this sauce is intoxicating if you eat too much.
For this recipe you may select any type of pears you like or are available. All common European pear varieties, such as d’Anjou, Bartlett or Bosc all originate either in the 18th or 19th centuries and are not what the Romans would have eaten. I am not aware of an original Roman or Greek pear variety from the Roman period available today on the market.
As far as wines go, there are still wines commonly available today which are made from grape varieties that were used by the Romans. One such wine is called Muscat of Samos, made from the sweet Muscat grape, grown on the island of Samos in Greece. A good brand of this wine is Kourtaki and and it is available in many wine stores in the US. I have used Kourtaki Muscat of Samos sweet white wine for my recreation of this recipe.