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Isinglass Jelly, Constantia
Dissolve an ounce of the best isinglass in a pint of water. Put to it a quarter of a pound of good loaf sugar, and part of the rind of a Seville orange, pared thin so as to leave none of the white skin. Simmer over a slow fire, add nearly a pint of Constantia, strain through a muslin, doubled three or four times, and mould when cool, carefully keeping back any sediment. As a general rule moulds should be soaked in water some two or three hours before they are used. Time, about fifteen minutes to simmer. Probable cost, 1s. 4d., exclusive of wine. Sufficient for two moulds.
A wine jelly from the era before packet gelatine, built on isinglass and a sweet Cape dessert wine. Two things decide whether it works: the strength of the setting agent against a high proportion of alcohol, and keeping the wine off the heat.
- Isinglass and its modern equivalentIsinglass is collagen from fish swim bladders, sold in shreds or leaf and dissolved by long soaking and gentle heat. It is still available from brewing suppliers, but for a jelly of this size 4 sachets (about 1 oz) of powdered gelatine, or the leaf equivalent, does the same work.
- Alcohol weakens the setNearly a pint of sweet wine in a quart of jelly is a heavy alcohol load, and alcohol interferes with gel formation. Err on the generous side with the setting agent, or the jelly will slump when turned out.
- Add the wine off the heatThe instruction to simmer applies to the water, sugar and peel only. Once the syrup is clear, draw it from the heat before stirring in the Constantia; boiling drives off both the alcohol and the muscat aroma that is the whole point of the dish.
- Loaf sugarLoaf sugar was hard refined sugar broken from a cone, prized because it was clean and dissolved without scum. Ordinary granulated sugar is the direct replacement, a generous half cup (about 115 g) for a quarter pound.
- Seville orangeA bitter marmalade orange, in British shops for only a few weeks in midwinter. Out of season, use the pared zest of a sweet orange with a strip of lemon zest to restore the sharpness. Take no pith, which turns the jelly bitter and cloudy.
- ConstantiaThe sweet wine of the Constantia valley near Cape Town. Klein Constantia's Vin de Constance, revived in the 1980s, is the nearest thing to the original; a Muscat de Beaumes-de-Venise or a good Moscatel is a workable stand-in.
- Straining and sedimentMuslin folded three or four times catches the fibre and undissolved matter from the isinglass. Let the jelly stand until barely warm, then pour it off the sediment rather than tipping the pan out, or the base of the moulded jelly will be gritty and dull.
- MouldsSoaking a metal mould for hours was to help release the jelly; a rinse in cold water immediately before filling achieves the same. To turn out, dip the mould in hot water for a few seconds and invert onto a wetted plate.
- Setting and yieldNo chilling time is given. Allow at least six hours in the refrigerator, preferably overnight. Two moulds of about a pint each will serve eight.
Isinglass reached British kitchens as an import, much of it from Russian sturgeon, and served two trades at once: it set jellies and blancmanges in the confectioner's larder and clarified beer and wine in the brewer's. Its use here reflects a period when a clear, quivering, unmoulded jelly was the mark of a competent dessert cook, and when the flavouring wine was as much a status claim as the shape of the mould. Constantia, from the vineyards outside Cape Town, was among the most celebrated sweet wines sold in Europe in the eighteenth and nineteenth centuries, ordered by European courts and turning up in English fiction as a restorative for low spirits.