Mushroom Soup
1/4 pound mushrooms (or skin and stems of 1/2 pound) 2 tablespoons butter 2 tablespoons flour 1 teaspoon salt 1 pint milk Brush, wash and skin the mushrooms. Put the skins to simmer in a little water. Cut the mushroom caps and stems into very small pieces; add one pint of water and simmer until tender. Make a sauce of the fat, flour, salt and milk and add the water in which the mushroom caps, stems and skin were cooked. The soup is more delicious if the diced caps and stems are added.
A plain white-sauce soup that stretches a quarter pound of mushrooms with their own cooking liquor. The technique is sound; only the proportions and a few assumptions need adjusting.
- Do not let the sauce boil hard after the liquor goes inThe milk-and-flour base will thin and can catch on the bottom once the mushroom water is added. Bring it just to a simmer, stirring, and hold it there until it thickens to the consistency you want.
- Skinning mushroomsPeeling the caps is called for in many older recipes, from a time when mushrooms often reached the kitchen unwashed and gritty. Cultivated white or cremini mushrooms need only a wipe or a quick rinse, so the peeling can be skipped and the whole quarter pound used, stems included.
- The stem-and-skin versionThe parenthetical is a thrift measure: trimmings from half a pound of mushrooms used for another dish. Save stems and trimmings in the freezer and they will make this soup at no extra cost.
- Fat"The fat" in the method means the two tablespoons of butter. Cook the flour in it for a minute or two before adding milk, or the soup tastes pasty.
- Liquid volumeA pint of milk plus a pint of mushroom water gives about a quart, but much of the mushroom water simmers away. Measure what is left and top up with water or stock to bring the total to a quart.
- Simmering timeNo time is given for the mushrooms. Small pieces are tender in 10 to 15 minutes; the skins can go 20 to 30 minutes to draw out colour and flavour, then be strained out.
- SeasoningOne teaspoon of salt for a quart is a moderate seasoning, and there is no pepper at all. Taste at the end and add white pepper, and a grating of nutmeg if you like.
- YieldAbout a quart, which serves four as a first course.
Cream soups built on a butter-and-flour sauce thinned with a vegetable's own cooking water were a staple of American cookery-school teaching from the late nineteenth century onward, and this recipe follows that pattern: a fixed ratio of butter, flour, salt and milk, with the vegetable supplying the flavour. The instruction to peel the caps and simmer the skins separately suggests mushrooms that reached the kitchen with soil still on them, and the frugal alternative of using nothing but skins and stems suggests they were not a cheap ingredient. The final line, that the soup is better with the diced mushrooms left in, may be a quiet argument against straining a cream soup perfectly smooth, though the recipe does not say so.