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Tomato Catsup
8 quarts tomatoes 1/2 quart cider vinegar 1/4 cup salt 1/4 teaspoon red pepper 1/2 tablespoon black pepper 1 head garlic or 1/2 onion 1/2 ounce whole cloves Cut the tomatoes in pieces and stew them until soft; press through a sieve to remove the skins and seeds; add the other ingredients; mix thoroughly and boil about three hours or until reduced one half. Bottle without straining and seal.
The proportions and the flavouring are sound, but the preserving method is not: this is a hot-fill-and-seal with no measured processing step and very little added acid for the volume of tomato. The notes below explain the specific problems rather than offering a corrected procedure.
- Why the seal is the problemThe recipe says only "bottle without straining and seal." There is no boiling-water processing, no time, and no temperature. Tomato pure0e sits on the borderline of the safe-acid range, and open-kettle sealing with no measured process is exactly the situation in which surviving Clostridium botulinum spores may germinate; the spores are not destroyed by the three-hour simmer. Any current tested tomato ketchup recipe specifies a measured processing time in a boiling-water canner; use one of those instead.
- Not enough vinegar to guarantee acidityHalf a quart of cider vinegar to eight quarts of tomatoes is roughly one part vinegar to sixteen parts tomato before reduction. Tomatoes sit on the borderline of the safe-acid range, commonly cited at about pH 4.0 to 4.6, which is why tested recipes now specify added acid. Reduction concentrates sugar and solids as much as acid, so it cannot be assumed to fix the pH.
- Nineteenth-century vinegar was not standardisedVinegar strength is unstated -- Household cider vinegar of this period varied in strength, and the recipe gives no percentage. Without a known acetic acid content there is no way to calculate the finished acidity, which is the whole basis of safe tomato preserving.
- The salt is for flavour, not preservationA quarter cup of salt across four quarts of finished catsup works out to roughly two percent by weight. That seasons the sauce; it does nothing to inhibit spore-forming bacteria.
- The three-hour boilLong open reduction was the standard route to a thick catsup before commercial tomato paste existed. It concentrates the sauce and drives off water, and it will kill yeasts, moulds and vegetative bacteria, but boiling at 212F does not destroy botulinum spores. Cooking time is not a substitute for canning process.
- Quantities, for referenceEight quarts of cut tomatoes is roughly 14 to 16 lb, yielding about four quarts of finished catsup after reduction by half. Half an ounce of whole cloves is a generous two tablespoons, and a whole head of garlic here is used as a single flavouring unit, not clove by clove.
- Whole spice, unstrainedThe instruction to bottle without straining leaves the whole cloves, the pepper and the garlic in the jar. Flavour will go on developing in storage, and clove in particular tends to become dominant with time.
Tomato catsup began as one of a large family of English ketchups — thin, dark, keeping sauces built on mushrooms, walnuts, anchovies or oysters, the name generally traced to a Malay or Hokkien word for a fermented fish brine. The tomato version took hold in America through the nineteenth century, settling into the recognisable form here: sieved pulp, vinegar, salt, clove and pepper, boiled down for hours until it coated a spoon. Catsup was seasonal work, made in quantity when tomatoes were cheap and glutting, and bottled to carry a household through winter. Commercial bottlers were already competing hard for that market in the same decades.