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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Preserving and Canning Fruit and Vegetables: Prepare
Cauliflower.-Prepare in summer the same as for serving at table.
Pack in jars and sterilize.
Carrots and Parsnips. - Gather in early summer when the young plants are tender and sweet. Prepare as for serving at table and sterilize as for corn.
Turnips and Kohl-Rabi. - Prepare as for the table, pack and sterilize.
Lima Beans. - Pick before the pods begin to harden and treat as for corn.
Pumpkin or Winter Squash.-Preserve these in their natural condition in a suitable storeroom as long as possible.
But should they show signs of decay, steam and can the same as summer squash. By this time the jars which have been emptied of other vegetables will be available and may thus be made to do double service. - Succotash.
Gather fresh corn and beans early in the morning. Prepare and sterilize as above. This is one of the most difficult things to can, hence boil an hour and a half each day as for summer squash.
Vegetable Roast. - Prepare corn, lima beans, tomatoes, stringbeans, okra, squash and eggplant as for canning separately. Mix in any desired proportions but let the corn and lima beans predominate. Add two or three medium sized onions to each quart and run through a food chopper to mix thoroughly. Pack into jars and sterilize by boiling an hour and a half each day for three days as for summer squash. To prepare for the table mix an equal amount of bread crumbs, add a piece of butter the size of a walnut and one egg. Season to taste with pepper and salt and bake in a round baking dish until brown. Cut into slices like a meat loaf and serve hot with drawn-butter sauce.
Or corn, okra and tomatoes mixed in equal proportions may be canned as soup stock.
These are instructions for putting up low-acid vegetables by repeated boiling-water processing, a method that was standard in household manuals of the period and is now known to be unsafe. The notes below explain what the text is describing and why the method fails.
- Why this cannot be doneCauliflower, carrots, parsnips, turnips, kohl-rabi, lima beans, corn, squash and mixed vegetables are all low-acid foods, with pH well above 4.6. Clostridium botulinum spores can survive hours of boiling at 212F; they are only reliably destroyed at 240-250F, which requires a pressure canner. Nothing described here ever reaches that temperature.
- The "boil an hour and a half each day for three days" methodThis is intermittent or fractional sterilization, sometimes called Tyndallization. The theory was that each boiling killed the vegetative bacteria and the intervening warm days coaxed surviving spores into germinating so the next boiling would catch them. In a sealed jar of low-acid vegetables the interval instead provides the oxygen-free, room-temperature conditions in which surviving spores can produce toxin. Longer boiling does not compensate.
- Succotash and the Vegetable Roast are the worst casesThe author admits succotash is "one of the most difficult things to can." Corn and lima beans are dense and starchy, which slows heat penetration to the jar's center, and the ground, packed Vegetable Roast is denser still. Dense, starchy low-acid products of this kind are among those implicated in home-canning botulism cases.
- Botulinum toxin gives no warningUnlike spoilage organisms, it need not produce gas, off odor, cloudiness or a bulging lid. A jar can look and smell sound and still be lethal in very small amounts. Tasting to check is not a test.
- If you want to put these vegetables upUse a current pressure-canning schedule from the USDA Complete Guide to Home Canning or a state extension service, which gives tested times and pressures for each vegetable and jar size. Freezing is the simpler route for corn, lima beans and squash.
- The serving instructions, read separatelyThe baked loaf at the end is an ordinary vegetable dish and does not depend on the canning method: mixed cooked vegetables bound with an equal volume of bread crumbs, one egg and one to two tablespoons of butter (a "piece the size of a walnut"), baked until browned. Made with fresh or safely preserved vegetables it is a perfectly good supper dish.
- Drawn-butter sauceNot clarified butter. In American cookbooks of this era it means a light sauce of butter, a little flour and hot water or stock, whisked smooth and seasoned — closer to a thin butter velouté.
- Food chopperA hand-cranked meat grinder clamped to the table. A food processor pulsed a few times gives a similar coarse, uneven texture; a blender will not.
Household Discoveries belongs to a wave of early twentieth-century American home manuals that urged families to put up their own vegetables as a matter of thrift, and the small economy of reusing "the jars which have been emptied of other vegetables" for late-season pumpkin is entirely in that spirit. The intermittent boiling method it recommends came out of nineteenth-century bacteriology, where repeated gentle heatings were a recognized way to sterilize laboratory media, and it was carried into domestic canning by analogy. Clostridium botulinum had in fact been identified in Belgium in the 1890s, following an outbreak traced to cured ham, but the link between the organism and home-canned low-acid vegetables was not widely understood until the 1910s and 1920s, when American investigators documented a string of outbreaks and pressure canning began to be promoted in earnest. Pages like this one are a useful record of the moment just before that shift: careful, frugal, methodical, and wrong about the one thing that mattered most.