Wine Soup
Mix rapidly on the fire 1 quart of white wine, 1 quart of water, 1 tablespoonful of cornstarch, yolks of 6 eggs, juice and rind of a lemon, and 4 tablespoonfuls of sugar. Stir it, but do not let it boil, for 20 minutes. Then add the beaten whites, sweetened with sugar, and put on ice to cool.
A cold wine custard, thin enough to drink from a cup. Everything depends on keeping it below a simmer.
- The hinge: no boilingSix yolks in an acidic, watery liquid will curdle the moment the pan reaches a simmer. Hold it at 170-180F over low heat or in a double boiler, stirring constantly, until it coats a spoon; the full 20 minutes is a guide, not a target.
- Quarts and proportionsTwo quarts of liquid to one tablespoon of cornstarch gives a barely thickened soup, so the body comes almost entirely from the yolks. If you want more than the faintest gloss, use two tablespoons.
- Slurry the cornstarch"Mix rapidly on the fire" glosses over the fact that dry cornstarch dropped into hot liquid lumps. Whisk it smooth with a little of the cold water first, then combine everything off the heat before warming the pan.
- Which white wineThe recipe says only 'white wine.' A dry, sharp white suits it: a Riesling, Gruner Veltliner or plain dry white works; skip oaked wines, and note that the alcohol is not cooked off at these temperatures.
- Lemon rindPare it in wide strips with no pith and fish it out before chilling. Grated zest left in the soup can leave a gritty texture and may turn bitter on standing.
- The beaten whites are rawThey are folded in after the pan leaves the heat and never cooked. Use pasteurized whites if anyone at the table is pregnant, elderly, very young or immunocompromised. Beaten whites also slacken and weep on standing, so beat and add them just before serving rather than before chilling.
- "Put on ice"An icebox instruction: set the bowl in a larger bowl of ice water, stir until cold, then refrigerate. A warm custard left to cool slowly in a deep bowl holds its heat, which risks both carry-over cooking and a long spell at warm temperatures.
- Yield and serviceTwo quarts plus the whites serves eight to ten as a first course, poured into cups or shallow bowls with a spoonful of the meringue floated on top.
Wine soup is Weinsuppe, a staple of German and Austrian domestic cooking that appears in nineteenth-century household manuals both hot as an invalid dish and cold as a summer Kaltschale "cold bowl" served like a chilled fruit soup. The technique is simply a thin custard sauce made with wine in place of most of the milk, finished with floating sweetened whites. A dish that reads oddly to an American cook, sugar and egg and a quart of wine offered as soup, was exactly the sort of thing worth bringing home. Sweet soups of this kind survived longest in Scandinavian and Central European kitchens, where they still turn up as a first or last course rather than a dessert.