Ratafia Blancmange

A very simple set cream: crushed almond biscuits infused into scalded cream, then set with isinglass. Almost everything hinges on the setting agent, which no longer means what it did.

• Isinglass to gelatineIsinglass is dried sturgeon swim bladder, sold in leaf or shred form and largely gone from kitchens. Its setting power varies a great deal by grade, so the ounce called for here cannot be converted exactly; leaf or powdered gelatine at the strength given on the packet for one quart of liquid is the practical substitute.
• Imperial measuresThe vocabulary (gill, ratafias, isinglass) points to a British book; on that reading the quart is 40 fl oz, about 4 3/4 US cups, and a gill is 5 fl oz, half an imperial cup.
• RatafiasRatafia biscuits are small, dry, crisp almond macaroons, close kin to amaretti and sold as such today. Half a pound is a large quantity of biscuit to a quart of cream; the result is thick and almost pudding-like rather than a delicate jelly.
• Dissolve the gelatine separatelySoften and dissolve the setting agent gently on its own, then stir it into the cream once the cream has cooled to warm rather than boiling; brief heat is harmless, but prolonged boiling can weaken the set.
• Strain before mouldingThe macaroons will never fully dissolve into smoothness. Pass the mixture through a sieve before it goes into the mould if you want a clean texture, and skim any froth from the surface, since froth becomes an unattractive crust once set.
• Setting and turning out"Set it to cool" means several hours in the cold; overnight in the refrigerator is safest for a quart mould. Rinse the mould with cold water first, and dip it briefly in hot water to release the blancmange.
• YieldA quart mould serves six to eight. It is rich, so small portions with fresh fruit or a spoonful of preserve suit it better than large ones.