Lentil Soup
1 cup dried lentils 2 teaspoons salt 1 tablespoon butter 1 tablespoon flour 1 tablespoon lemon juice 2 slices onion 1 small bay leaf 1 1/2 quarts water Put the lentils, bay leaf and onion to boil in the water, and cook slowly for three hours or until tender. Then put through a colander. Rub the flour and butter together, and stir in a little of the soup; then add this to the whole of the mixture, and boil five minutes. Add the salt and lemon juice just before serving. This should make one quart of soup. If not, add water sufficient to make this quantity.
A plain purée soup from the meatless-cookery tradition, built on nothing but lentils, aromatics and a butter-flour thickening. Two details carry it: the lemon at the end, and the reduction down to a quart.
- Cooking timeThree hours likely reflects the older, longer-stored dried lentils of the period; the recipe itself allows 'or until tender'. Modern brown or green lentils are tender in 30-45 minutes; red lentils collapse in about 20. Check at 30 minutes and keep going only if they still have a core.
- Salt goes in late for a reasonSalt goes in late -- The recipe holds back the two teaspoons until serving. The soup reduces considerably, so salting early risks overshooting; the older claim that salted water slows the softening of pulses is disputed. Two teaspoons in one quart is on the assertive side; add half, taste, then adjust.
- "Put through a colander"This means pressing the cooked lentils through with a wooden spoon or pestle to make a purée and hold back skins and bay leaf — a coarse sieve, not a drain. A food mill on the medium plate does the same job; an immersion blender gives a smoother result and keeps the skins in, which is no loss.
- The rouxRubbing butter and flour together raw and slackening it with hot soup makes a beurre manié, not a cooked roux. The five-minute boil afterwards is what cooks out the raw flour taste, so do not shorten it.
- Yield and consistencyOne quart from a cup of lentils and six cups of water means the soup loses roughly a third of its liquid over the long simmer. With a modern 40-minute cook you will lose less, so expect a thinner, larger yield — either simmer uncovered to reduce, or accept a lighter soup. As written it serves four as a first course.
- Lemon juiceAdded off the heat, it does the work salt cannot: lentil purée is flat without acid. A tablespoon per quart is a starting point, and a second one is rarely wrong.
- Seasoning latitudeThe base takes well to a clove of garlic with the onion, a scrape of nutmeg, or a spoon of good olive oil at the table.
Lentils are among the oldest cultivated foods in the Near East and Mediterranean, and they earned a durable place in vegetarian and Lenten cooking for an obvious reason: cooked dried pulses supply substantial protein without meat. Books of this kind proliferated in Britain and America from the late nineteenth century onward, driven partly by organised vegetarian societies, partly by the era's enthusiasm for food reform and dietary science, and later by wartime economy. The technique here is thoroughly conventional for the period — long boil, sieve, thicken with butter and flour — and the finishing lemon juice is the one flourish, a habit generally traced to Middle Eastern lentil cookery, where acid and pulse have been paired for a very long time.