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Nuns' Biscuits
Take four ounces of sweet almonds, and five or six bitter ones. Blanch them, and pound them in a mortar to a smooth paste, and keep dropping a little orange-flower water on them to prevent them oiling. Rub the yellow rind of two large fresh lemons upon half a pound of loaf sugar, crush the latter to powder, sift it well, and mix it with the almonds; add two ounces of dried flour, a table-spoonful of finely-minced candied citron, the yolks of six eggs well beaten, and last of all the whites whisked to a firm froth. Put a spoonful or two of the mixture into some small patty-pans well buttered, and bake in a moderate oven. When they are brightly browned, turn them out of the pans, put them upon baking-tins, and place them again in the oven to harden. Time to bake, about twenty minutes. Probable cost, 1s. 6d.
This is a macaroon-type almond biscuit, and the problem is in the first line: the five or six bitter almonds are not a flavouring quirk but a genuine toxic ingredient.
- Bitter almonds are the reason to stopBitter almonds contain amygdalin, which releases hydrogen cyanide when the nuts are crushed and wetted — exactly what pounding them in a mortar with orange-flower water does. Hydrogen cyanide is volatile and much of it is driven off by heat, but the amount remaining after baking is not something you can measure at home, and the margin in a small cake eaten by a child is not one worth testing.
- You cannot buy them anywaySale of raw bitter almonds for eating is prohibited in the United States and restricted in many other countries. What is sold today as "bitter almond" is almost always an essence or oil from which the cyanogenic compounds have been removed, which is not the ingredient this recipe assumes.
- Apricot and peach kernels are not a substituteThey are sometimes suggested as a stand-in because they carry the same marzipan aroma. They carry it for the same chemical reason and present the same hazard. If you want an almond biscuit of this type, use a current recipe.
- What the archaic terms mean, for reading purposesLoaf sugar is hard refined sugar broken from a cone, hence the crushing and sifting; rubbing it against lemon rind was a common way to extract citrus oil. "Dried flour" is flour warmed in a low oven to drive off moisture, and patty-pans are small shallow tartlet or bun tins.
- The two-stage bakeThe second spell in the oven, out of the tins and on flat baking-tins, is a drying stage rather than a baking one — the same logic as drying out macaroons or rusks so they keep in a tin. It tells you these were meant as a storable sweet biscuit, not a fresh cake.
Nuns' biscuits belong to a long European tradition of convent confectionery: enclosed communities with time, sugar, almonds and eggs to hand produced marzipans, macaroons and dried almond biscuits that circulated well beyond the cloister, and Iberian, Italian and French convents were famous for them into the nineteenth century. Names like this are usually generic rather than traceable to one house. The bitter almonds are the period detail worth noticing \— a few bitter kernels among the sweet ones were the ordinary way to get that intense almond perfume before commercial flavouring essences, and Victorian cookery books print the instruction without comment. The 'Probable cost' formula suggests a source of the Cassell's type, compiled for middle-class households in the 1870s and after, which prices each dish: 1s. 6d. reflects sugar and almonds still being counted as small luxuries.