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Tomatoes
Scald the tomatoes and remove the skins. Put them in a porcelain-lined kettle, bring slowly to a boil, simmer thirty minutes. Put them boiling hot into the jars, fasten the lids and stand in a cool place. When cold again screw the lids and keep them in a dark, dry closet. Tomatoes are easiest of all vegetables to keep.
This is open-kettle canning, a method that was standard in home kitchens for decades and that no current food-safety authority accepts. The problems are specific and they are not fixed by longer simmering.
- No processing in the jarThe tomatoes are boiled in the kettle, then poured hot into jars that are simply closed and left to cool. Nothing sterilises the headspace, the jar rim, the lid or the surface of the food after filling, and the seal that forms as the jar cools is unreliable and unverifiable.
- Clostridium botulinumA sealed, oxygen-free jar held at room temperature in a dark closet is precisely the environment in which botulinum spores germinate and produce toxin. Spores survive 30 minutes at boiling point; only a measured process — boiling-water bath at a tested time, or pressure canning — brings the risk into range.
- Tomatoes are no longer reliably acidicThe book's confidence that "tomatoes are easiest of all vegetables to keep" rests on their acidity. Some cultivars, and any over-ripe or frost-touched fruit, can sit above pH 4.6, the line below which botulinum cannot grow. Current practice requires measured added acid — bottled lemon juice or citric acid — per jar, which this recipe has none of.
- "Fasten the lids" then "screw the lids"This two-stage closing points to a rubber-ring jar of the period, though the recipe does not say which type. Modern two-piece lids seal by vacuum during processing and behave differently; the instruction cannot be carried across to current equipment.
- A failed seal is not always obviousBotulinum toxin does not reliably produce swelling, off odour or visible spoilage. Tasting to check is not a test. Home-canned tomatoes of unknown provenance or method should be discarded, not sampled.
- What to do insteadUse a current, tested recipe from a food-preservation authority for canning tomatoes, or freeze the cooked tomatoes, which sidesteps the question entirely. Read this page as a record of how it was once done.
Open-kettle canning — pack boiling hot, seal, trust the heat — was the ordinary domestic method through the nineteenth century and well into the twentieth, and tomatoes were its poster child. The Mason jar was patented in 1858 and spread from the 1860s onward, and tomatoes are often said to have been among the foods most readily put up at home once it was available: cheap in glut, and acidic enough that failures were, by common account, uncommon enough to breed confidence. That confidence is what you hear in the closing line. Systematic testing of home canning came later, through agricultural experiment stations and extension services, and it steadily narrowed the list of foods and methods considered safe; open-kettle processing was eventually dropped altogether. The recipe also shows its age in the porcelain-lined kettle, specified because tomato acid attacks bare iron and copper and picks up a metallic taste — enamelled and stainless pans have made that instruction invisible rather than obsolete.