Home › Desserts › Prune Sponge
Prune Sponge
Soak one pound of French prunes over night in enough water to cover them. In the morning, stew in the same water until tender. Add one cup of sugar, and put through a sieve to retain all stones and skins. To the pulp, add one-half box of Larkin Gelatine softened in one-half cup of water, the juice of one lemon and one orange. Beat until foamy. Then add the stiffly beaten whites of two eggs and beat again until all are thoroughly mixed. Mold.
A gelatin-set prune mousse of the sort that filled the dessert chapter of every early twentieth-century household book. It works well, but two things in the original need translating: the gelatine measurement and the temperature at which you fold in the whites.
- The hinge: temperature of the pulpThe gelatine must be dissolved in the prune pulp while it is still hot, then the mixture cooled until it is thick and syrupy but not set before the whites go in. Fold whites into hot pulp and they collapse; fold them into set gelatin and you get streaks and lumps that no amount of beating will fix.
- "One-half box of Larkin Gelatine"Granulated gelatine of the period was sold in paper boxes of small envelopes, but box and envelope sizes varied by brand and the Larkin box size is not recorded, so half a box cannot be pinned down. The original is genuinely ambiguous. Judge by liquid instead: this yields roughly 3 1/2 to 4 cups of pulp and juice, which wants about two modern 1/4 oz envelopes (4 1/2 teaspoons) for a mousse that holds a mold but still spoons softly.
- French prunesDried plums, sold as prunes or dried plums today. "French" most often pointed to the large Agen-type fruit, though it could also mean prunes imported from France. Modern prunes are sold pitted and are moister than 1900 stock; overnight soaking is optional and simmering until fully tender, often well under an hour, is enough.
- SievingA pound of prunes cooked down is stiff work through a fine sieve. A food mill or the coarse disk of a ricer does the same job, and pitted fruit can go straight into a blender or processor. If the fruit is pitted, the sieve is only removing skins.
- SugarOne cup with a pound of modern prunes plus orange juice is very sweet. Half to two-thirds of a cup is closer to current taste.
- Raw egg whitesThe whites are never cooked. Use pasteurized whites in carton form if you are serving anyone elderly, pregnant, very young or immune-compromised; whipped aquafaba also folds in acceptably here, though it is less stable overnight.
- Molding and yieldRinse the mold with cold water rather than oiling it, and chill at least four hours or overnight. Serves six to eight. Unmold by dipping the base in warm water for a few seconds and inverting onto a cold plate; whipped cream or a thin custard is the traditional accompaniment.
Prune desserts of this kind belong to the moment when packaged granulated gelatine turned an expensive, laborious preparation into a cupboard staple. Prepared and sheet gelatine had been commercially available from the mid-nineteenth century, but by 1900 a boxed envelope did the work, and household cookbooks filled with whips, sponges, snows and Bavarian creams built on the same formula of sweetened fruit pulp, gelatine, citrus juice and beaten whites. The brand name in the ingredient list is the tell: cookbooks of this era were often issued or underwritten by the companies whose products they specified, and readers were expected to recognize the brand as one already in the house. Prunes suited the method perfectly, since they were cheap, kept well on the shelf, and gave a dessert deep color and body in the months when no fresh fruit was to be had.