To Cure Pork
First sprinkle little salt over the pork, then lay it in a vat four or five days, then put the pork in a barrel and cover each layer with salt. The barrel must be kept well covered. Next make a brine strong enough to float a potato, and add to two hundred pounds of meat, two ounces of saltpetre.
This is a working farm note rather than a recipe: it assumes a cellar at winter temperature, a cooper's barrel, and a butcher who already knows what the brine should look like. As written it cannot be followed safely, and the points below explain where it breaks down.
- No measured brine"Strong enough to float a potato" is an old density test for a strong brine, but how strong varies with the potato, its age and the water temperature. Safe curing depends on a known salt concentration by weight, and this instruction does not provide one.
- Saltpetre out of rangeSaltpetre -- Two ounces of potassium nitrate to two hundred pounds of meat gives no practical control: the recipe does not say how it is to be distributed through the meat, and nitrate works only as it is slowly converted to nitrite by bacterial action. Modern curing uses a premixed nitrite cure at a specified rate per pound precisely because an unverifiable nitrate figure gives no assurance either way.
- No temperature givenFour or five days in a vat, then weeks in a barrel, is only safe below about 40F throughout. The original assumes a cold winter cellar and says nothing about it; at room temperature the interior of a ham spoils long before salt penetrates.
- Botulism is the specific riskBotulism is a risk -- A low-oxygen, salted, unrefrigerated meat mass is a setting in which Clostridium botulinum can grow. Nitrite in a controlled amount is what suppresses it, which is one reason the vague saltpetre figure matters rather than being a quaint detail.
- ScaleTwo hundred pounds of pork is most of a hog. Nothing in the method scales down usefully: the saltpetre is the only stated ratio, and the salt is not measured at all.
- What the vessels wereThe "vat" was an open tub used for the first salting, before the meat went into the barrel, a tight-staved wooden cask. Neither has a straightforward modern kitchen equivalent.
- If you want to cure porkUse a current recipe with cure weights, brine percentages and holding temperatures stated in numbers.
Salt pork and barrelled bacon were the backbone of the American winter larder well into the twentieth century, and instructions like this one circulated as reminders rather than teaching text: hog killing happened in cold weather, and the printed note only had to fix the proportions. Saltpetre, or potassium nitrate, had been used for centuries to keep cured meat red and to prevent the spoilage that cooks recognised long before anyone identified the bacterium responsible; the float test for brine strength appears in nineteenth-century farm manuals as a rule of thumb for near-saturated salt, usually with an egg, though a potato is sometimes named instead. Entries like this one survive in general household cookbooks mainly because the audience still included readers with a cellar, a barrel and a pig.