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Canned Tomatoes
Wipe tomatoes, cover with boiling water, and let stand until skins may be easily removed. Cut in pieces and cook until thoroughly scalded; skim often during cooking. Fill jars, following directions given.
This is open-kettle canning: hot food ladled into jars and sealed with no measured processing time, no temperature, and no added acid. It was standard practice in 1896 and is no longer considered safe for tomatoes.
- Why the method failsFilling jars with hot food and sealing them does not heat the sealed jar contents enough to destroy Clostridium botulinum spores, and the vacuum formed as the jar cools is unreliable. The recipe defers to "directions given" elsewhere in the book; as far as can be judged, those general directions carry no processing time or water-bath step that meets modern standards.
- Tomatoes are borderline in acidityTomatoes sit close to pH 4.6, the line below which botulinum spores cannot germinate. Modern cultivars, over-ripe fruit and fruit from dead or frost-killed vines can test above that line, which is why current guidance requires measured added acid — bottled lemon juice or citric acid — in every jar. This recipe adds none.
- Skimming and "thoroughly scalded"Neither instruction is a food-safety control. "Thoroughly scalded" gives no core temperature and no hold time, so there is nothing here to reproduce or verify.
- The jars themselvesThe sealing hardware assumed in 1896 — zinc caps, glass lids, rubber rings — cannot be evaluated for seal integrity the way a modern two-piece lid can. Any surviving instructions written for that hardware do not transfer.
- Botulism is not detectable by inspectionSpoiled low-acid canned goods can look, smell and taste normal. There is no home check that substitutes for correct processing, which is why this one cannot simply be watched carefully instead.
- If you want to can tomatoesUse a current tested recipe from a food-preservation authority, with its stated acidification and its stated processing time for your jar size and altitude. Read this page as a historical document.
Canning chapters were a common feature of late nineteenth-century cookbooks, because glass jars with screw or clamp closures had by then put summer preserving within reach of ordinary households rather than commercial packers. Tomatoes were among the most commonly put up crops: prolific, cheap in season, and useful all winter in soups and sauces. The brevity here is telling — Fannie Farmer's book treats canning as a known routine and simply refers the reader back to general directions, which is exactly the assumption that made open-kettle canning so persistent. The science that overturned it came later; the role of acidity in controlling botulinum, and the need for measured processing schedules, were worked out through the twentieth century, largely through agricultural extension and public-health research. Recipes like this one are the reason that work was necessary.