Kirsch Sauce

A two-ingredient dessert sauce that depends entirely on restraint: the cream must stay soft enough to pour and the kirsch must not be stirred in hard enough to break it.

• A gill and a halfA gill is 4 fl oz (half a cup) in American measure and 5 fl oz imperial, so this is somewhere between 3/4 cup and a scant cup. The word "only" appears to be the point of the recipe: a tablespoon of spirit in much more cream than that will barely register.
• Whipped, then measuredThe text is ambiguous about whether the gill and a half is measured before or after whipping. Read it as 3/4 cup of whipped volume, which comes from roughly 6 tablespoons of heavy cream; a full 3/4 cup of liquid cream whips to nearly double and will swamp the tablespoon of kirsch.
• KirschwasserA clear, unsweetened cherry eau-de-vie, usually 40% alcohol and bone dry. The sweetened red "cherry brandy" sold as a liqueur is not a substitute and will turn the sauce pink and cloying.
• Soft peaks onlyStop whipping while the cream still slumps. Alcohol thins cream, so a stiffly beaten base will loosen into something grainy once the kirsch goes in; a soft one settles into a pourable sauce.
• Fold, do not stirAdd the kirsch in a thin stream down the side of the bowl and turn it through with a spatula in a few strokes. "Gently mix" is doing real work here — overworking at this stage curdles the fat and weeps liquid.
• The cold sauceboatChill the serving bowl beforehand, and a cold mixing bowl helps too. Cream stabilised only by cold and air slackens quickly at room temperature, which is why this is best made just before it goes to table rather than held.
• Yield and useAbout 3/4 cup, enough for four to six servings spooned over poached or stewed fruit, a plain sponge, or a chocolate pudding. Serving it separately, as directed, keeps it from melting into a hot dessert.
• No sugarNone is called for, and none is wanted if the dish beneath it is sweet. Add a teaspoon of sifted confectioners' sugar only when the sauce is going onto something plain.