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 an open-kettle canning method for a low-acid vegetable mixture, and it is one of the genuinely unsafe procedures in the nineteenth-century canning literature. The points below explain the specific failure rather than offering a revision.
- The hinge, and why it failsEverything here depends on fifteen or twenty minutes of boiling being enough to make the jars keep. Boiling water reaches only 212F, which kills yeasts, molds and vegetative bacteria but not the heat-resistant spores of Clostridium botulinum. In a sealed, oxygen-free jar of low-acid food those spores germinate and produce toxin, which is odorless and tasteless.
- Corn is low-acidSweet corn sits around pH 6.0 to 6.8. Corn is the classic low-acid canning vegetable and requires processing at temperatures above boiling, which a porcelain kettle on the stovetop cannot produce.
- The tomatoes do not acidify the mixtureIt is tempting to assume two-thirds tomato makes this a tomato pack. It does not. Adding a substantial proportion of low-acid corn raises the pH of the jar contents, and canning guidance treats tomatoes combined with low-acid vegetables as a low-acid product regardless of the ratio, rather than as tomatoes.
- "Can immediately" is open-kettle canningFilling and sealing hot jars with no processing after sealing was standard practice in the 1870s and is no longer considered safe for anything. It relies on the food's own heat to sterilize the jar and lid, and gives no reliable vacuum or verified seal.
- Tin cans at homeThe tin option assumed a household able to solder a cap onto a can. Home can-sealing equipment is not part of a modern kitchen, and solder of the period commonly contained lead.
- "Keep in the dark"This instruction is about appearance, not safety. Light bleaches the color out of canned tomatoes and dulls the corn. It tells you nothing about whether the contents are sound.
- If you want canned corn and tomatoesUse a current, tested pressure-canning recipe for a low-acid vegetable mixture, which specifies jar size, headspace, pounds of pressure and processing time. Nothing in the original can be adjusted into that.
Buckeye Cookery and Practical Housekeeping came out of Ohio in the 1870s, at the moment when home canning shifted from an experiment to a routine part of the domestic year. The Mason jar and its zinc screw cap had been patented in 1858, and by the time this book was compiled a farm kitchen could put up its own garden surplus in glass rather than depending on crocks, drying racks and salt. Recipes like this one, contributed by name from the book's network of Ohio housewives, record what people actually did: boil the vegetables in a porcelain-lined kettle so the acid would not attack bare iron, fill the containers scalding hot, and trust the heat of the food to do the rest. The organism behind botulism was identified by bacteriologists in the 1890s, but its implications for home canning were not widely acted on until the early twentieth century, when the U.S. Department of Agriculture began promoting the pressure canner for low-acid foods. Corn and tomatoes together is a durable American pairing that survives as a stovetop succotash and a canned staple; the sealing method here is the part that did not survive.