Home › The World's Kitchen › Cream of Fresh Mushrooms
Cream of Fresh Mushrooms
Wash in plenty cold water three-quarters of a pound fresh mushrooms, drain on a cloth and finely slice them. Heat one ounce butter in a large saucepan, add the mushrooms and gently fry ten minutes, occasionally stirring meanwhile. Lift them from pan with a skimmer and pound to a pulp in a mortar. Add two and a half ounces flour to the mushroom butter in pan; stir with wooden spoon while heating two minutes. Moisten with a quart and a half broth and a pint milk, add mushrooms with a medium, sliced white onion, two branches parsley, one branch chervil, a teaspoon salt, two saltspoons cayenne pepper and a saltspoon grated nutmeg; mix well until it comes to a boil. Let boil thirty-five minutes. Dilute two egg yolks with two gills cream and juice of a quarter of a lemon, add it to the soup with half ounce good butter, mix while heating without boiling five minute. Remove, strain cream through a sieve into a basin, then through a cheese-cloth into a soup tureen and serve.
A classical French cream soup written in the ounces-and-gills idiom of a professional kitchen. The whole thing hangs on the last step, where the egg-and-cream liaison goes in.
- Never let it boil after the yolksOnce the two yolks, cream and lemon juice are stirred in, hold the soup below a simmer — around 175F — for the five minutes given. A boil will scramble the yolks into grains that no amount of straining will disguise, and the lemon juice makes curdling likelier still.
- UnitsA gill is half a cup, so two gills of cream is one cup. A saltspoon is a quarter teaspoon. One ounce of butter is two tablespoons; two and a half ounces of flour is a scant two-thirds cup by volume.
- The cayenne is heavy-handedTwo saltspoons is half a teaspoon of cayenne in a soup that is meant to taste of mushroom and cream. A pinch, or a quarter teaspoon of white pepper, is closer to what a modern palate expects from a potage crème.
- Washing the mushroomsThe recipe washes them in plenty of cold water and drains them on a cloth. Keep the contact with water brief and dry them well; the ten-minute fry in butter is where the flavor is made, and wet mushrooms will steam instead.
- Mortar workA food processor does in fifteen seconds what the mortar does in five minutes. Pulse the cooked mushrooms to a coarse paste rather than a purée — everything is strained at the end anyway.
- ChervilRarely stocked; it is faintly aniseed and parsley-like. A little tarragon plus extra parsley is the usual substitute, or leave it out.
- The long boilThirty-five minutes is there to cook out the flour and reduce the two quarts of liquid. Stir the bottom now and again; a flour-thickened soup at that depth scorches quietly.
- Double straining and yieldSieve first to catch the solids, then pass through cheesecloth for the smooth finish. The liquid called for comes to a little over two quarts before the boil, so expect roughly two quarts finished, enough for six to eight as a first course.
This is the French potage crème de champignons in the manner of the professional kitchens of the turn of the twentieth century: mushrooms sweated in butter, a flour roux slackened with broth and milk, a long cooking to smooth out the starch, and a finish with yolks, cream and acid — the liaison that separates a cream soup from a plain thickened one. The double straining, first through a sieve and then through cheesecloth, and the chervil alongside the parsley both suggest a professional rather than a domestic hand. The cultivated white mushroom was grown commercially in the disused quarries under and around Paris, which is why it is called the champignon de Paris in French to this day. A soup calling for three-quarters of a pound of fresh mushrooms was not an economy dish.