Potato Soup
Six large potatoes sliced and boiled in enough water to cover, season with salt, and pepper, a little butter, and 1 cup of sweet cream or milk.
A bare-bones formula of the kind that assumed the cook already knew what soup should look like. The whole character of the dish rests on how much of the cooking water you keep.
- The hinge: don't drainThe potatoes are boiled in "enough water to cover" and that starchy water becomes the body of the soup. Drain it and you are left with mashed potato needing liquid; keep it and the soup thickens on its own as the slices break down.
- Sweet cream"Sweet" here means fresh rather than sugared, as opposed to the soured or clabbered cream that was common in a farm kitchen. Ordinary heavy cream or whole milk is the equivalent.
- QuantitiesSix large potatoes is roughly 2.5 to 3 lb, and a good potful of soup for four to six. "A little butter" is unquantified; a tablespoon or two is a reasonable reading.
- Which potatoA floury variety such as russet will collapse and thicken the broth; waxy potatoes stay in slices and give a thinner, more brothy result. The recipe does not specify.
- Add the dairy lastPour in the cream or milk off the heat, or over a very low flame. Boiled hard after the dairy goes in, milk can curdle.
- TextureThe original expects some slices to hold and some to fall apart. Mashing part of the pot against the side with a spoon, or a few pulses with a stick blender, gives a smoother soup without turning it gluey the way full blending will.
- SeasoningPotato absorbs a great deal of salt and this soup will taste flat if seasoned once. Salt the cooking water, then correct again after the cream goes in.
Potato soup of this kind is less a dish than a default: potatoes, water, salt, whatever dairy the house had, and the pot on the back of the stove. Recipes like this filled American compilations because the potato was cheap, stored through winter in a cellar, and turned into supper without a butcher. The specification of "sweet" cream is the period detail worth noticing — in a kitchen without reliable refrigeration, cream that had turned was a daily fact and had its own uses, so a recipe had to say which one it meant. Books titled along the lines of Reliable Recipes are often said to have been community or promotional collections, printed with contributions from local cooks, and their brevity may suggest a reader who wanted little more than the proportions confirmed.