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Isinglass and Gelatine Jelly
When jelly is to be made for the table, isinglass and gelatine are frequently used instead of calf's foot stock, and possess the advantage of being made much more easily and quickly. From isinglass especially, many wholesome and agreeable dishes may be made. It is, however, difficult to give the exact proportions to be used, as isinglass differs so much in quality. The best may be known by its dull-looking, hard skin, and by its requiring fully half an hour's boiling to dissolve it. The commoner kinds dissolve very quickly, and may be known by their white, fine appearance. When good isinglass is used, one ounce will stiffen a pint and a half of jelly. Simmer the isinglass, until it is thoroughly dissolved, in a pint of water. Just before it is taken from the fire, add a tea-spoonful of strained lemon-juice, a table-spoonful of cold water, and a lump of sugar. Let all boil together two or three minutes, and remove the scum carefully as it rises. Strain through a jelly-bag, add wine, lemon-juice, sugar, and flavouring according to taste, and pour into a damp mould. Let the jelly remain in a cool place until it is firm. Gelatine is more frequently employed than isinglass. Allow an ounce of gelatine for a pint of liquid. In cold weather, or when using small moulds, more liquid may be taken. Soak the gelatine for an hour, pour boiling liquid upon it, and stir it over the fire until dissolved. Clarify with white of egg. (See CALF'S FOOT JELLY.)
This is a method rather than a fixed recipe, and the two setting agents it describes have had very different fates: gelatine is on every supermarket shelf, while isinglass has all but left the domestic kitchen. The proportions given are also far stiffer than modern taste allows.
- The pint is an imperial pint20 fl oz, or roughly 2 1/3 US cups (568 ml). Every ratio below shifts accordingly, so scale before you weigh anything.
- Gelatine strength has changedAn ounce of gelatine to a pint of liquid gives a rubbery, cuttable jelly of the sort Victorian cooks wanted for elaborate turned-out moulds. Modern powdered gelatine is standardised and generally sets more strongly: roughly 1/4 oz (one 7 g sachet) will set a US pint to a light set, and about 1/2 oz per imperial pint is usually enough for a jelly that will stand unsupported when demoulded.
- IsinglassIsinglass is dried collagen from the swim bladders of sturgeon and related fish. It is still sold, mostly to brewers and to conservators as an adhesive, and the food-grade grades are expensive and variable, which is precisely the inconsistency the text complains about. There is no reason to hunt for it here; leaf or powdered gelatine does the same work predictably.
- Do not boil the gelatineThis is the hinge. The isinglass instructions call for prolonged simmering and a two- or three-minute boil, which suited a tough raw material, but gelatine loses setting power if held at a rolling boil. Soak it, dissolve it in liquid that is hot but below simmering, and stir until no grains remain on the back of the spoon.
- Soaking timesAn hour's soak suits the gelatine of the period. Modern leaf gelatine blooms in cold water in five minutes; powdered gelatine needs about ten minutes sprinkled over a few tablespoons of cold liquid.
- Clarifying with white of eggWhisk the whites (and crushed shells, if you like) into the cool liquid, bring it up slowly without stirring so the raft forms and traps the cloud, then strain. A jelly bag is a felt or flannel cone; a double layer of damp muslin in a sieve does the same job. Let it drip and never squeeze, or the jelly clouds again.
- Wine and acidAdd the wine, lemon juice and flavourings off the heat so the aromatics survive, and taste while warm — jelly reads noticeably less sweet and less flavoured when cold. Very acidic additions weaken the set, so err on the firmer side if you are using a lot of citrus.
- The mould"Damp" means rinsed with cold water and not dried, which helps the jelly release. Set in the refrigerator rather than a cool larder; allow four to six hours, or overnight for a large mould. A pint of jelly needs a mould a little larger than a pint.
Before commercial gelatine, table jellies depended on boiling down calves' feet for their collagen, an all-day business with an unmistakable smell, which is why this entry treats isinglass and gelatine as labour-saving marvels. Isinglass had long been the fining agent of the brewery and the confectioner's standby, and by the second half of the nineteenth century British households could, broadly speaking, buy branded packet gelatine and sheet isinglass by weight, so the cook's problem shifted from extraction to judging quality — slow-dissolving isinglass is the good stuff, while the commoner kinds are white, fine and quick-dissolving. The clear moulded jelly it produced was a status dish as much as a dessert: transparency proved careful clarifying, and the ornamental copper moulds of the period were designed to show it off. The cross-reference to calf's foot jelly is a reminder that the older method was still in the book, and that jelly was also fed to invalids, on the widely held Victorian belief that it was strengthening — a claim nutrition has since retired.