To salt hams
For three hams, pound and mix together half a peck of salt, half an ounce of salt prunella, three ounces of salt petro, and four pounds of coarse salt; rub the hams well with this, and lay what is to spare over them, let them lie three days, then hang them up. Take the pickle in which the hams were, put water enough to cover the hams with more common salt, till it will bear an egg, then boil and skim it well, put it in the salting tub, and the next morning put in the hams; keep them down like pickled pork; in a fortnight take them out of the liquor, rub them well with brine, and hang them up to dry.
This is a dry-then-brine cure for three whole hams, written for a cold larder and a wooden salting tub. The quantities of curing salts are far outside any modern safe range and the meat weight is never stated, so the recipe cannot be scaled or corrected with confidence.
- Why the nitrate is the problem"Salt petro" is saltpetre (potassium nitrate) and "salt prunella" is the same compound fused and cast into cakes, so the recipe calls for roughly three and a half ounces of nitrate for an unspecified quantity of pork. Modern curing limits nitrate and nitrite to a few hundred parts per million of meat weight, measured on a scale; blind rubbing at this rate can leave dangerous residues in the outer flesh.
- No meat weight, no ratio"For three hams" gives no weight at all, and hams varied widely in size. Every safe cure is a percentage of a known weight, which is exactly the information the receipt omits.
- No temperature anywhereThe hams sit three days dry, then a fortnight in brine, then hang to dry, with no indication of how cold the room must be. Curing depends on holding the meat near 36-40F throughout; at room temperature a large ham spoils from the bone outward before salt reaches the centre.
- The egg test is not a measurementBrine strong enough to "bear an egg" indicates only a strong brine, and the reading shifts with brine temperature, egg age and egg size. It tells you nothing about nitrate concentration, which is the part that matters for safety.
- Cold-smoked or air-dried, never cookedNever cooked in this receipt -- Nothing in this process brings the pork to a safe temperature; the recipe ends with rubbing the hams with brine and hanging them up to dry. A dry-cured ham eaten without cooking relies entirely on correctly measured salt, nitrate, water activity and temperature control to suppress Clostridium botulinum and other pathogens, and none of those four are specified here.
- For the record on the unitsA peck is 8 dry quarts, so half a peck is a substantial bulk of salt, on top of the four pounds of coarse salt named separately. "Keep them down like pickled pork" means weight the hams under a plate or board so they stay fully submerged.
- If you want to cure a hamUse a current recipe from a food-science or extension source that gives cure quantities by weight of meat, a specified nitrite or nitrate product, and holding temperatures.
Domestic curing receipts of this kind belong to a period when a household killed its own pigs in late autumn and had to make the meat last until spring, and when the salting tub was a standing item of kitchen furniture rather than a project. Coarse salt drew out water, while saltpetre and its fused form, salt prunella, kept the cured flesh red instead of grey; both were sold by apothecaries as well as by grocers. Salt prunella is usually said to have taken its name from its use in medicine for sore throats, though that derivation is traditional rather than settled, and it survived in cookery books long after its medical use faded. The egg-flotation test for brine strength was still cited in nineteenth-century manuals for want of a hydrometer, and the fortnight in pickle followed by hanging is a common English farmhouse sequence.