Home › Preserving › String Beans
String Beans
Snip the ends of the beans, remove strings if present, leave the beans whole or pile a quantity together, and cut them in inch or half-inch lengths straight across the pods or diagonally as desired; wash in cold water, then fill into sterilized jars, shaking down meanwhile. Set the filled jars into the steam cooker or other appliance, the covers beside them. Put lukewarm water into the cooker, cover, and let the jars heat gradually, then fill each jar to overflow with boiling water; cover and let cook undisturbed until the beans are tender enough for the table; adjust the rubbers; add salt, a teaspoonful to a quart, - - to a pitcher of boiling water and use to fill the jars to overflow; set the lids in place; again cover and let cook about twenty minutes; fasten the rubbers securely and remove the cans to a board.
When cold, store in a dark place.
This is a boiling-temperature process for a low-acid vegetable, and it is the single clearest example of a canning method that food science has since ruled out. The notes below explain the terms and why the method fails.
- Why it fails: temperatureGreen beans are low-acid, with a pH typically around 5.4 to 6.0. Clostridium botulinum spores survive prolonged boiling at the 212F a steam cooker or boiling-water bath can reach; only pressure canning, which holds the jar contents near 240F, reliably destroys them. Nothing in this procedure ever gets above boiling.
- Why it fails: the sealed jarA sealed jar of moist, low-acid vegetables at room temperature is close to an ideal anaerobic environment for botulinum toxin production. The toxin is odourless and tasteless, and the jar need not bulge or smell off. Storing "in a dark place" affects colour only and does nothing to inhibit the organism.
- Why the salt does not preserveA teaspoonful of salt to a quart is roughly 6 g in about a litre of brine, under 1 percent. That is a seasoning level. Salt begins to inhibit bacterial growth at concentrations many times higher, as in a proper brine cure.
- "Cook until tender enough for the table"The instruction sets doneness by texture rather than by a measured time at a measured temperature. Modern process schedules exist precisely because the lethality of a heat treatment cannot be judged by how soft the beans have become.
- "Rubbers" and "cans"The recipe assumes glass jars with a separate rubber gasket ring and a clamped or screwed glass lid, the standard closure of the period. Those rings perished with age and reuse, and the seal was adjusted mid-process here, which breaks sterility. The hardware has been obsolete for decades.
- The steam cookerAn early twentieth-century "steam cooker" was a tiered vented steamer sitting over a stove burner, not a pressure vessel. It cannot substitute for a pressure canner.
- If you want canned beansUse a current tested process from a pressure-canning authority, or freeze the beans instead. Do not adapt the procedure above.
Books of this vintage were written in the window between the spread of home canning and the research that made it safe. Through the 1890s and 1900s, household manuals routinely gave open-kettle, boiling-water and "intermittent" processes for every vegetable, including beans, corn and peas, on the reasonable-sounding theory that repeated or prolonged boiling would eventually kill whatever was in the jar. Heat-resistant bacterial spores were understood in the laboratory well before the message reached the kitchen, and a run of botulism cases traced to home-canned low-acid vegetables in the 1910s and 1920s pushed United States agricultural researchers to work out processing times at pressure rather than at the boil. The pressure canner and published process schedules came out of that work, and the recipe above is a fair snapshot of what careful, well-meaning household practice looked like just before it changed. The mention of a steam cooker is itself a period detail: those tiered stovetop steamers were sold as labour-saving appliances for everything from puddings to preserving, and their presence in the instructions shows how far canning had already moved out of the commercial cannery and into the ordinary kitchen.