Stirling Sauce

A creamed-butter dessert sauce of the hard sauce family, softened with warm milk and wine rather than served stiff. The printed ingredient list has come down incomplete, so the proportions need judgement.

• Missing quantitiesOnly the milk and wine are given amounts; the sugar and butter that the method calls for are not stated in this text. Something on the order of 1/3 cup butter and 1 cup sifted confectioners' sugar would suit 3 tablespoons milk and 2 tablespoons wine, but that is a reconstruction; the original figures are genuinely lost here.
• The hinge: keep it warm, not hotThe instruction closing the original is the whole technique. Creamed butter loses its body as it nears its melting point, somewhere around 90F; if the sweetened milk goes in hot the butter melts and the sauce is liable to separate into a greasy pool.
• Add slowly, off the heatTreat it like a mayonnaise. Dribble the warm sugar mixture into the creamed butter a spoonful at a time, beating between additions, so the liquid stays emulsified in the fat.
• Sugar typeConfectioners' or superfine sugar is the safer choice; granulated may not dissolve fully at this temperature and can leave the sauce gritty.
• The wineSherry, Madeira or a sweet white would all suit. The alcohol is not cooked off, so it reads plainly in the finished sauce; use something you would drink.
• Double boilerA heatproof bowl over barely steaming water does the same job. Keep the water off the boil and the bowl clear of it.
• Yield and servingAt the reconstructed proportions above, roughly a cup, enough for about six servings. Serve it soft and cool over steamed or cottage pudding, apple dumplings or plum pudding. Best made the same day; refrigeration sets it hard.