Everlasting Syllabub

An 18th-century whisked syllabub, the kind that was beaten to a stiff foam and left to stand rather than drunk at once. The recipe as printed here breaks off partway through the sugar, so the finishing instructions have to come from the general method.

• The half pintsA British half pint is 10 fl oz, so read each as about 1¼ cups. Cream and wine in equal volume, as here, will thicken given a long enough beating, though period whisked syllabubs vary in ratio and often use rather more cream than wine.
• Thick creamThis is best read as a rich cream comparable to modern double cream, roughly 48% butterfat. Use heavy or whipping cream at 36% or above; anything lighter, including half-and-half or single cream, will not hold a foam against that much wine and acid.
• Sugar quantityThe entry stops at "half a pound" without naming what it belongs to. Half a pound of sugar to a pint of liquid is very sweet by modern taste, and it is safer to sweeten to taste than to assume the larger figure.
• Essence of the rindRubbing lump sugar over a lemon until the sugar is yellow and oily draws out the peel oil — what is now called an oleo-saccharum. Granulated sugar rubbed with a wide strip of zest, or zest muddled into the sugar and left half an hour, does the same work.
• The wine"White wine" in this period leaned towards Rhenish, sherry or Madeira rather than a dry modern table white. A medium sherry or a fruity off-dry white gives a closer result; a lean Sauvignon Blanc reads thin and sour against the cream.
• Whisking, not foldingThe hinge of the dish is patient beating. Combine everything, let the sugar dissolve fully, then whisk steadily until a thick froth rises. Lift it off with a skimmer into a sieve set over a bowl to drain, and only glass up the foam that has stopped weeping.
• Why "everlasting"Properly drained, the foam stands in the glass for several days without collapsing or separating — that is the whole point of the name. Overwhipping past the froth stage turns it grainy and buttery, so stop as soon as it holds its shape.
• YieldA pint of liquid in total gives six to eight small glasses. Serve chilled in tall narrow glasses with a spoon, and provide sponge fingers or a thin biscuit alongside.