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Potato Soup
3 potatoes 2 ounces butter 1 egg 1 pint hot milk Salt and pepper Pare and cut the potatoes in quarters; cover with boiling water and boil five or six minutes. Place in the cooker for one and a half hours. While mashing, add the butter and pour in gradually the boiling milk. Season with salt and pepper. Stir and strain and heat again. Beat the egg and put into tureer; pour over it the soup.
The ingredient list as printed is incomplete — the potatoes and butter appear only in the method, with no quantities — so this is a sketch to be filled in rather than a recipe to follow line by line. A pint of milk and one egg suggest a modest batch.
- Quantities to supplyFor 1 pint (2 cups) of milk, use about 1½ lb potatoes and 2 tablespoons butter. That yields roughly four cups of soup, or three servings.
- What the cooker isA fireless cooker was an insulated box: food was brought to a hard boil on the range, then sealed in with heated soapstone discs or simply its own heat to finish by retention. The five or six minutes of boiling is not cooking time, it is charging the cooker with heat.
- Doing it on the stoveWithout a fireless cooker, simmer the quartered potatoes in their water until tender, 15–20 minutes, and skip the hour and a half. A slow cooker on low for 2 hours is the nearest equivalent in spirit.
- Boil hard before it goes inWith any retained-heat method the food must be at a rolling boil going into the insulation, and the vessel must be full and lidded. A pot only half filled loses heat too fast to finish the potatoes.
- Add the milk boilingThe instruction to pour in boiling milk gradually while mashing keeps the soup hot; cold milk would cool the potato, and it is commonly said to give a pasty texture.
- Strain, then reheat gentlyPush the soup through a sieve rather than blending it. Potato starch turns to paste under a blade. Reheat to just below a boil.
- The egg in the tureen"Tureer" is a typographical error for tureen. Beating an egg in the serving bowl and pouring the hot soup over it thickens and enriches the soup, but a single egg meeting four cups of liquid may not reach 160°F throughout. Use a pasteurized egg, or temper the beaten egg with a ladle of hot soup and return it to the pan over low heat.
- SeasoningPotato and milk absorb a great deal of salt. Season after straining, when the soup is at its final volume, and taste again once it is hot.
Fireless cookery had a real vogue in American households between roughly 1900 and the 1920s, and cookbooks of the period often gave it its own chapter. The principle is simple insulation: food heated to boiling and then packed in a tightly closed, straw- or felt-lined box goes on cooking for hours without fuel, which mattered when the alternative was keeping a coal or wood range burning through a summer afternoon. The method was promoted heavily by domestic-science writers as a saving in fuel, labor and kitchen heat, and commercial cookers were sold alongside homemade versions built from packing crates. Potato soup is a natural candidate — starchy, forgiving, and needing long gentle heat rather than close watching — and the finish of a beaten egg in the tureen is an older European habit, the same trick behind egg-thickened broths from Greek avgolemono to the liaisons of classical French soup-making.