Tomato Catsup
To every gallon of tomatoes put four tablespoons salt, four tablespoons black pepper, one tablespoon cayenne pepper, three tablespoons mustard, one-half tablespoon ground cloves, the same of allspice; after having washed and cut up the tomatoes, boil them about twenty minutes, strain them, add the spices, etc., and simmer the whole together three hours; then bottle and seal.
This is a home-canning recipe, and it is the canning rather than the cooking that fails modern standards. The notes below explain what the original is doing and why the finished bottles are not safe.
- No acid at allCurrent tested tomato ketchup recipes rely on vinegar, both for flavour and to push the pH below 4.6, the line above which Clostridium botulinum can grow. This recipe contains none. Spices, mustard and salt at these levels contribute nothing meaningful to acidity.
- Tomatoes are not reliably acidTomatoes sit close to the safety line, roughly pH 4.2 to 4.9, and modern low-acid varieties, over-ripe fruit and fruit from stressed plants sit on the wrong side of it. A nineteenth-century cook could not measure this; the recipe simply assumes tomatoes preserve themselves.
- "Bottle and seal" is not a processFilling hot bottles and closing them with cork, wax or a screw cap gives a seal but no measured heat treatment. Three hours of open simmering at around 100C kills spoilage organisms and vegetative bacteria but not botulinum spores, which survive and then find a sealed, low-oxygen, low-acid bottle waiting for them.
- Salt far below preserving strengthFour tablespoons of salt to a gallon of pulp is a seasoning level, not a preserving level. Salt-cured and brined goods use far higher concentrations than this. Nothing here is inhibitory.
- A gallon of tomatoesFor context, the original quantity is about 8 lb of cut tomatoes by volume, reducing over three hours to perhaps a quart of thick sauce. That long reduction is what gave old catsups their dark colour and near-black spice flavour.
- Ground spice ratiosFour tablespoons of black pepper and one of cayenne to a gallon is aggressively hot by modern taste, and the "mustard" here is most likely dry powder rather than prepared mustard, though the recipe does not say. Catsups of this kind were used by the spoonful, closer to a Worcestershire sauce than to the sweet ketchup we know.
- If you want to make catsupUse a current tested recipe with measured vinegar and a specified boiling-water process time. Do not adapt this one.
The word travelled a long way before it reached tomatoes: catsup, ketchup and catchup are all generally traced to a Southeast Asian fermented fish sauce, kê-tsiap, picked up by English traders and applied at home to any thin, spiced, long-keeping condiment. Through the eighteenth century English catsups were made of mushrooms, walnuts, oysters and anchovies; tomato versions are an American development of the early 1800s, and by the time this book was printed nearly every household manual carried one. What makes this example characteristic of its period is the spicing and the reduction rather than sugar and vinegar — sweet, sharp, thick ketchup is largely the legacy of commercial bottlers late in the century, who also had to answer public argument about the chemical preservatives that kept unacidified catsup from spoiling on a grocer's shelf. Recipes like this one, sealed and stored on the strength of long boiling alone, are exactly the practice that argument was about.