No. 95

To Prepare Pig's Skin Gelatine

Pour Preparer la Colle de Couenne

Soak in cold water for five or six hours, six pounds of fresh pork skin; put it into a saucepan with cold water to double its height, and blanch it in this water until it boils, then drain and refresh it; scrape off the pieces one by one, wash them well, and return them to the saucepan with more clean, cold water and boil the liquid while skimming it; set it on one side of the range or on the gas stove, and add half a bottleful of white wine, then continue boiling for seven hours, skimming it frequently. Pass the liquid through a sieve into a basin, let it get cold and firm on ice, then remove all the fat from the top and wash the surface off with very hot water; melt it once more to mix it in with the necessary broth and clarify it with meat and eggs or white of eggs, proceeding the same as for aspic-jelly (No. 103).

← No. 94 To Prepare Gelatine from Calf's Feet Elementary Methods No. 96 Gherkins →

For the Modern Kitchen

This is not a dish but a kitchen staple: a stock so rich in collagen that it sets hard, used to give body to aspics, chaud-froid sauces and galantines. It is the professional ancestor of the packet of powdered gelatine.

The hinge: keep it barely simmeringRanhofer says to set the pan "on one side of the range" after it comes to a boil, which usually indicates a gentle simmer rather than a full boil. A hard seven-hour boil will emulsify fat into the liquid and cloud it, and the later clarification may not fully recover it.
Pork skinAsk a butcher for fresh (not cured or smoked) skin, or buy skin-on pork belly and pare it. Six pounds is a professional batch; a quarter of that works on a domestic range with the wine and water scaled down proportionally.
Half a bottleful of white wineA 19th-century wine bottle was close to today's 750 ml, so this is roughly 1 1/2 cups. Use something dry and unoaked; the acid helps extraction and the alcohol cooks off entirely over seven hours.
Blanch, refresh, scrapeThe first boil is discarded on purpose. It carries off blood, scurf and any bristle, and the scraping afterwards is where the finished jelly gets its clean flavour. Skipping it gives a stock that tastes distinctly of pig.
"Refresh" means cold waterDrain the blanched skins and plunge them into cold water so you can handle them for scraping. It is not a rinse for cleanliness alone.
Chilling and degreasing"Firm on ice" simply means refrigerate overnight. The fat lifts off in a solid cap; the hot-water rinse of the surface removes the last greasy film, which otherwise shows as a dull bloom on a finished aspic.
Test the set before you commitCollagen yield varies with the skin. Chill a spoonful on a saucer: it should be firm enough to hold a cut edge. Too soft, reduce further; too rubbery, dilute with broth when you melt it down.
Yield and keepingThe recipe gives no water measure beyond covering to double the skin's height, so the yield will vary with how hard you reduce. It keeps about four days refrigerated, or freeze it in blocks and melt as needed; repeated reboiling weakens the set.
Where it goes nextOn its own this is unseasoned and unclarified. It is meant to be melted into broth and clarified with lean meat and egg white following the aspic method the book cross-references, which is what turns it into something you would actually serve.

A Little History

Colle de couenne translates literally as pork-rind glue, and the word colle is honest about the kitchen's debt to the glue-maker's trade: both trades boiled hides and skins for hours to extract collagen, and only the standard of cleanliness differed. Charles Ranhofer, who ran the Delmonico's kitchens in New York and published The Epicurean in 1894, placed this among the Elementary Methods alongside gelatine from calf's feet because a large restaurant kitchen went through jelly constantly, for aspic moulds, glazed cold birds, chaud-froid coatings and the mirrored surfaces of a buffet piece. Commercial sheet gelatine existed by then and Ranhofer uses it elsewhere in the book, but a house-made rind stock carried flavour and a particular tender-firm set that dry gelatine does not, and pork skin was effectively free. The seven-hour extraction and the repeated skimming are the marks of a brigade kitchen with a cook to spare and a range that never went out.