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Lamprey, Potted
Take a dozen lampreys of moderate size. Empty them, and cleanse them thoroughly from slime by washing them in hot water, cut off the heads, tails, and gills, and take out the cartilage, and a string on each side of it, down the back. Dry them well, and let them drain for several hours before proceeding further. Pound half a dozen blades of mace and a dozen cloves to a fine powder. Mix with them two ounces of white pepper, and three ounces of salt, and sprinkle this seasoning inside, and all over the lampreys. Curl the fish round, and lay them in a stone jar. Pour over them half a pound of melted beef suet, and two pounds of clarified butter. Tie three or four folds of paper over the top of the jar, and bake in a moderate oven. Keep looking at them whilst baking, and as the oil works up remove it. Lay them in a cool dry place, in the same jar in which they were cooked. When wanted for use, put as many as are required into a fresh jar, let them heat in the oven, then cover them with fresh butter. They will keep good for four or five months. Time, three hours to bake. Probable cost, uncertain, lampreys being seldom offered for sale.
This is a preserving recipe, not a dinner recipe: the fish is baked under fat and then held in the same jar for months. That storage method is the reason it cannot be attempted, and a few of the terms are worth decoding for anyone reading it as a historical document.
- Why it fails: fat-sealed fish at room temperatureBaked fish sealed under suet and butter and kept for "four or five months" in a larder is a textbook anaerobic, low-acid, low-salt environment. Clostridium botulinum spores survive baking and grow without oxygen; fish is one of the classic vehicles for botulism. The salt here (three ounces across a dozen fish, unevenly rubbed) is nowhere near a measured cure, and no acid, nitrite or verified temperature is involved. A current, tested recipe should be used for any preserved fish.
- Reheating does not fix itThe instruction to warm the pot and top it with fresh butter when wanted was the period's whole safety system. Botulinum toxin is not reliably destroyed by gentle oven warming, and the topping-up simply renews the anaerobic seal.
- Lamprey blood and slimeLamprey blood is known to contain a haemolytic, irritant compound, so handling the raw fish is not merely a matter of fastidiousness. The original directs that the fish be cleansed of slime by washing in hot water before anything else is done.
- The speciesSea and river lamprey are protected or restricted in much of Europe and the fish is listed under EU habitats legislation; in North America the sea lamprey is an invasive pest subject to control programmes rather than a market fish. Cassell's own note that lampreys are "seldom offered for sale" was already true in the 1870s.
- Reading the seasoningMace is the outer sheath of the nutmeg, sold in "blades" — dried strips — rather than ground; six blades is a modest amount by volume once ground. Two ounces of white pepper and three of salt for twelve fish is a heavy dry rub by modern eyes, but far short of the salt load a real cure requires.
- The vessel and the ovenThe "stone jar" is a glazed stoneware crock, and the three or four folds of paper tied over the top are a cover rather than an airtight seal. The book gives no temperatures; in a coal range "a moderate oven" meant the falling heat after the bread was drawn.
Lamprey — a jawless, eel-shaped fish that fastens onto other fish with a rasping sucker — was a prestige food in medieval and early modern England, valued because its dense, oily flesh ate like meat and could be served in Lent. Gloucester's lamprey pies, sent to the sovereign at Christmas and later at coronations, are the best-known survival of the trade, and the death of Henry I is traditionally attributed to "a surfeit of lampreys" (a story repeated in the chronicles rather than a medical diagnosis). Potting is the English answer to French confit: cook the flesh, pack it into a crock, and cap it with clarified fat to exclude air, which let a seasonal glut of Severn lampreys be eaten for months and shipped inland. By the time Cassell's compiled this entry the fish had largely dropped out of the market, which is why the book cannot even quote a price — the recipe survives as a record of an older luxury rather than as a practical instruction.