Lemon Sauce
2 teaspoons arrowroot. 1 cup sugar. 2 cups boiling water. Grated rind and juice of 1 lemon. 1 tablespoon butter.
Few grains salt.
PROCESS: Mix arrowroot, sugar and salt, pour on boiling water slowly, stirring constantly. Cook over hot water twenty minutes, stirring constantly the first five minutes, afterwards occasionally. Remove from range. Add lemon juice, rind, and butter in small bits. Beat well and serve hot.
The printed ingredient list is incomplete — arrowroot, sugar and boiling water all appear in the method but never in the list. Read the process closely before you start.
- Missing quantitiesThe original gives only the lemon, butter and salt. Period lemon sauces of this type generally run about 1 tablespoon arrowroot to 1/2 cup sugar and 1 cup boiling water, but that is inference from contemporary practice, not from this page. Treat the amounts as your own decision.
- Arrowroot behaves unlike flourIt thickens at a lower temperature, sets clear rather than cloudy, and thins if held at a hard boil. The double boiler in the instructions is doing real work: it keeps the sauce below boiling for the whole twenty minutes.
- "Cook over hot water"A double boiler, with the water beneath simmering and not touching the upper pan. A heatproof bowl over a saucepan does the same job.
- Twenty minutes is generousArrowroot clears and thickens within two or three minutes of contact with near-boiling liquid. Why the recipe holds it so long is not stated; five to eight minutes gives a thickened sauce, and after the first few minutes only occasional stirring is needed, as the recipe itself allows.
- Lemon last, off the heatAcid held with hot starch can break the thickening down and thin the sauce, which is likely why the recipe has you remove the pan from the range before the juice goes in.
- Butter in small bitsBeating the butter in off the heat, a bit at a time, is what gives the sauce its gloss and body; the recipe's 'beat well' is doing that work.
- ZestGrate the rind before juicing, and take only the yellow — the white pith is bitter and will not soften in a sauce cooked this gently.
- YieldNot stated, and not calculable from the page as printed; on the inferred quantities above it would come to roughly a cup. It is a pouring sauce, not a curd, and should coat a spoon thinly.
Lemon sauce is the standard American accompaniment to the plain steamed and baked puddings that anchored winter dinners — cottage pudding, gingerbread, suet or fruit puddings. The use of arrowroot rather than flour marks it as a slightly more refined version; arrowroot was imported (largely from the West Indies) and cost more, but produced a clear, glossy sauce where flour gives an opaque one, and it was also widely recommended for invalid and children's cookery as being easily digested. The double-boiler method reflects a range-cooking kitchen, where a pot set over water was the most reliable way to hold a sauce below boiling on a stove with no temperature dial.