Posset Syllabub

An "everlasting" or whipped syllabub: acid, alcohol and sugar are folded into cream and beaten until the mixture holds. The hinge is the whisking — stop while it is thick but still pourable, because the wine and lemon juice have already begun to firm the cream and it will seize into grains if pushed.

• Quantities in imperial measureThis is a British book, so the quart is 40 fl oz (about 5 cups) and the pint 20 fl oz (2 1/2 cups). Scaling the whole thing to a quarter gives a manageable batch: 1 1/4 cups cream, a scant 2/3 cup wine, about 1/2 cup sugar plus the zest and juice of one lemon.
• Lump sugarLoaf or lump sugar was cut from a refined cone; a pound is about 2 1/4 cups of granulated sugar. That is a great deal of sugar by modern taste — half will still set the mixture and let the wine show.
• Thick creamUse heavy or double cream, 36 per cent fat or higher. Anything lighter will not carry the acid and alcohol without breaking.
• Rubbing sugar on the rindThis makes what is now called an oleo-saccharum: the sugar lumps abrade the peel and absorb the oil. A modern equivalent is to grate the zest of two or three lemons into the sugar and leave it half an hour, then add the juice and stir until dissolved.
• Whisk one way for half an hourThat is a hand-whisk instruction. With a stand mixer on medium, or a hand mixer, the same point arrives in three to five minutes. Watch it rather than timing it; the wine makes the margin between thick and curdled narrow.
• Which white winePeriod syllabubs leaned on sherry, Madeira or a sweet white. A dry white works but the result will taste sharp against so much lemon; a medium sherry or Sauternes-style wine is closer to the original intent.
• Standing and separationAn "everlasting" syllabub was praised for holding several days in a cool larder. In a modern refrigerator it will keep 24 to 48 hours, though a thin layer of wine whey may settle out beneath the foam.
• YieldAs written this fills roughly a dozen small glasses or custard cups. It is a spooned dessert, not a drink, and is best served very cold with a thin crisp biscuit.