Important: Safety Warning
This page describes home-canning methods from before the causes of botulism were understood. Canning low-acid foods without a pressure canner, as described here, can allow the growth of Clostridium botulinum, whose toxin is among the deadliest known. Follow current USDA home-canning guidelines instead.
This information has been left in for historical purposes but should not be acted upon.
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Canned Corn and Tomatoes
Scald, peel, and slice tomatoes (not too ripe) in the proportion of one-third corn to two-thirds tomatoes; put on in a porcelain kettle, let boil fifteen minutes, and can immediately in tin or glass (if glass keep in the dark). Some take equal parts of corn and tomatoes, preparing them as above. Others, after cutting the corn from the cob, cook it twenty minutes, adding a little water and stirring often, then prepare the tomatoes as above, cooking in a separate kettle five minutes, and then adding them to the corn in the proportion of one-third corn to two-thirds tomatoes, mixing well until they boil up once, and then canning immediately. - Mrs. D. Buxton.
This is a nineteenth-century open-kettle canning method for a mixture that is chemically incapable of being safely preserved this way. The notes below explain the specific failure points rather than offering a revised procedure.
- The pH problemSweet corn sits around pH 6.0-6.8, firmly in low-acid territory. Adding two parts tomato does not reliably bring the mixture below pH 4.6, the threshold under which Clostridium botulinum cannot grow. A corn-tomato mix is treated by every current guideline as a low-acid product regardless of the ratio.
- Boiling does not steriliseFifteen minutes at 212F kills vegetative bacteria but not botulinum spores, which survive several hours of boiling. Only temperatures around 240F, reached in a pressure canner, destroy them within a practical time. Nothing in this recipe ever gets above the boiling point of water.
- Open-kettle filling"Can immediately" means ladling hot food into jars and sealing, relying on the cooling contents to pull a vacuum. The seal that results is unreliable, and even a good seal creates exactly the oxygen-free environment in which surviving spores germinate and produce toxin.
- Tin cans at homeThe reference to "tin" is to hand-soldered cans sealed by the cook, often with lead-bearing solder. Beyond the seam quality, that is a lead exposure route as well as a preservation failure.
- Tomatoes "not too ripe"The instruction reflects a belief that underripe fruit was more acidic and firmer. Whether modern tomato cultivars are actually less acidic than nineteenth-century ones is disputed, but some varieties do test above pH 4.6, so the assumption behind the recipe cannot be relied on.
- No visible warningBotulinum toxin need not sour, cloud or smell the food. A jar can look and taste normal and still be lethal, which is part of why the risk in this method went unrecognised.
- If you want the dishCorn and tomatoes together freeze well, and current USDA and National Center for Home Food Preservation instructions cover pressure canning of corn and of tomato products separately. Use a current tested recipe rather than adapting this one.
The Dixie Cook-Book belongs to the great wave of American community and regional compilations of the 1880s, assembled from contributions signed with the names of local women — here Mrs. D. Buxton, whose three variant methods read like notes taken from neighbours who each did it slightly differently. Home canning had spread rapidly after the Civil War, helped by the Mason jar and by cheap tinware, and corn with tomatoes was one of the most attractive things to put up: both crops glut in late summer, and the combination reappears through the South and Midwest as a side dish and as the base of stewed-corn suppers. The porcelain kettle specified is enamelled iron, recommended because bare iron and copper discoloured acidic tomatoes. What the page cannot know is that the risks of putting up a low-acid vegetable were not yet understood: the organism responsible for botulism was identified in Europe in the 1890s, and safe processing times for low-acid vegetables were not worked out and published in America until well into the twentieth century.