Home › Ices, Preserves, and Confections › Lemon and Rhubarb Jam
Lemon and Rhubarb Jam
Scrape, slice, and weigh the rhubarb, allow 1 pound of sugar, chopped rind of 1 large lemon, and 1/2 ounce of bitter almonds, sliced, to each 1 1/2 pounds of rhubarb. Boil very gently, stirring often, for 1/4 hour. Add the juice of the lemons,-as many as are required in above proportions,--boil a little longer, until thick, and pour into jars. Put the nuts in a bag, and take them out before sealing. Young rhubarb needs about 3/4 hour to cook; old fruit requires 1 1/2 hours.
This one cannot be made as printed. The problem is not the rhubarb or the sugar but the half-ounce of bitter almonds steeped in every batch.
- Bitter almonds are the blockerBitter almonds contain amygdalin, which can hydrolyse to hydrogen cyanide when the kernels are cut and wetted; some of that cyanide is volatile and driven off in a long boil, but the recipe is asking for the toxic kernel specifically, for its benzaldehyde flavour, and sweet almonds are not a substitute in kind.
- The quantity is not trivialHalf an ounce of sliced bitter almonds to each pound and a half of rhubarb is roughly a dozen kernels per small batch, held at a simmer for anywhere from a quarter hour to an hour and a half. That is well above the range treated as safe in food today.
- The muslin bag does not make it safePutting the nuts in a bag and lifting them out before sealing removes the solids only. The water-soluble compounds the cook is after, and the cyanide released alongside them, stay in the jam. The bag is a straining convenience, not a barrier.
- Bitter almonds are not a shop ingredientRaw bitter almonds are not sold for eating in the United States and their sale is restricted in parts of Europe, which is why the ingredient reads as unfamiliar. Commercial almond extract supplies the same benzaldehyde note, either synthesised or from bitter almond oil from which the cyanide has been removed.
- The preserving method is also unspecifiedBeyond the almonds, the instruction is simply to pour into jars and seal, with no processing, no headspace and no cooling guidance. Rhubarb is acidic and sugar-heavy jams keep well, but a current tested preserving recipe should be used for the method as well as the flavouring.
- If you want lemon and rhubarb jamWork from a modern tested recipe. The rhubarb-to-sugar ratio and the long cook for older stalks in this book are unremarkable; the almond element is what has to go, and nothing here should be adapted around it.
Bitter almonds were a standard flavouring in nineteenth-century preserving and confectionery, valued for the marzipan-and-cherry note that comes from benzaldehyde, and English and American cookbooks called for them freely in ratafias, macaroons, blancmanges and jams. The danger was understood in outline — Victorian medical writing discusses prussic acid poisoning from almond essence — but no one had a way to measure the dose in a domestic pan. Rhubarb itself was a spring workhorse in these books: cheap, acidic, low in pectin, and available in quantity before other fruit arrived, which is why it turns up padded out with lemon rind and almond to give it a character of its own. With a Saucepan Over the Sea gathers dishes from a wide range of foreign cooking. Modern versions keep the lemon and drop the kernel.