Caper Sauce
3 tablespoons butter. 3 tablespoons flour. 1/2 teaspoon salt. 1/8 teaspoon pepper. 1½ cups strained mutton broth 1/2 cup capers. (or hot water).
PROCESS: Melt butter in a sauce-pan, add flour mixed with seasonings. Stir to a paste and pour on slowly broth in which mutton was boiled, first removing fat. Beat until smooth and glossy, add capers and heat to boiling point. Serve in sauce-boat.
A straightforward roux-thickened white sauce built on the water the mutton boiled in, meant to be spooned over boiled leg of mutton. The print is garbled in two places, so read the quantities with care.
- The measurementsThe printed page gives 1/8 teaspoon pepper and 1½ cups broth, as our text now reads. An eighth of a teaspoon is right for a cup and a half of sauce, where a teaspoon and a half would be overwhelming, and 1½ cups of liquid matches a roux of 3 tablespoons butter and 3 of flour.
- The hinge: skim the brothThe instruction to remove the fat first is the whole difference between a glossy sauce and a greasy one. Mutton fat is heavy and sets hard; chill the broth if you have time and lift the cap off, or blot the surface with paper.
- Add the liquid slowlyCook the butter and flour together a minute or two before any liquid goes in, then pour the hot broth in a thin stream while beating, as the recipe directs. Adding it all at once is what produces lumps.
- Capers and their brineHalf a cup of capers is generous by modern taste; a quarter cup may suit better. Drain them, and if you like the sauce sharper add a teaspoon of the brine or a squeeze of lemon at the end rather than more capers.
- Do not boil hard once the capers are inHeat just to the boiling point as directed. Prolonged boiling dulls the capers' pungency.
- If you have no mutton brothThe recipe offers hot water, which gives a very plain sauce. Lamb or a light chicken stock is a better substitute; season more assertively if you use water, since the broth was carrying most of the salt.
- YieldAbout 1½ cups, enough for six to eight servings alongside a boiled joint. It thickens as it stands, so thin with a spoonful of hot broth before serving if needed.
Caper sauce on boiled mutton is one of the fixed pairings of nineteenth-century English and Anglo-American cookery, and it appears in many general household books of the period. The logic is thrift as much as taste: the leg is simmered, the cooking liquor becomes the sauce, and nothing is wasted. Capers themselves are the pickled flower buds of Capparis spinosa, a Mediterranean shrub, and they reached northern kitchens by way of the bottled-goods trade, arriving in vinegar or brine in small jars that kept well on a pantry shelf. Their sharpness does the same work here that mint sauce does for lamb, cutting the fattiness of a mature sheep, which was a stronger, greasier meat than the young lamb usually sold today.