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Vegetables.-Asparagus
Trim the asparagus and throw the pieces into cold water. Then select quart jars. Arrange the asparagus butts down and thoroughly fill the jars. Throw straw or hay in the bottom of a wash boiler, or, better still, White jar holder, stand the jars on this and pour in sufficient cold water to nearly cover. Lay the lids on top, put the boiler over the fire and cover closely. Boil steadily three hours. Take up the jars, see that they are filled to overflowing. This
This is a home-canning procedure for a low-acid vegetable in a boiling-water bath, and it is the one category of old preserving instruction that current practice rejects outright. The notes below explain the failure rather than adapting it.
- Why the method failsAsparagus has a pH around 6.0, well above the 4.6 threshold below which Clostridium botulinum cannot grow. A sealed jar of plain asparagus is precisely the oxygen-free, low-acid, room-temperature environment in which the spores germinate and produce botulinum toxin.
- Boiling water is not hot enoughWater in an open boiler holds at 212F. Botulinum spores are not reliably destroyed below about 240F, which only a pressure canner reaches. Three hours at 212F cooks the asparagus to collapse without giving any dependable kill of the spores, and the long hold gives a false sense of thoroughness.
- No acid, no salt, no barrierThe recipe adds nothing at all — no vinegar, no brine, no measured salt. There is no second hurdle to fall back on if the heat process is inadequate, and here the heat process is inadequate by design.
- Lids laid on, not sealed"Lay the lids on top" is consistent with the older practice of leaving jars unsealed during processing and tightening afterward, though the recipe breaks off before it says so. Modern two-piece lids are not interchangeable with this sequence, and a jar that seals is not thereby safe.
- Toxin cannot be inspected forBotulinum toxin produces no reliable smell, taste, bulge or cloudiness. A jar processed this way can look and smell perfectly sound and still be lethal, which is why no visual check makes the method acceptable.
- The straw and the jar holderThe hay or straw in the bottom of the wash boiler, and the capitalised "White jar holder" offered as an improvement, apparently a branded device, simply keep the glass off the direct heat of the boiler bottom. A modern canning rack does the same job — but the vessel is the wrong vessel for this food regardless.
- The text breaks offThe passage ends mid-sentence at "This," so whatever the author said about sealing, cooling and storage is missing. Even setting safety aside, the instructions as printed are incomplete.
- If you want canned asparagusUse a current tested pressure-canning schedule from a food-safety authority, or freeze it. Do not adapt the procedure above.
Home canning of vegetables was a live and contested subject when this book was written. The cold-pack, long-boil method described here — pack raw, stand the jars in a wash boiler on straw, boil for hours — was the standard household technique of the late nineteenth and early twentieth centuries, and it worked well enough for acid foods like tomatoes, rhubarb and fruit that it was assumed to work for everything. The systematic research that separated low-acid from high-acid foods, and established that only steam under pressure reaches spore-killing temperatures, came later; pressure canners were commercial equipment before they were kitchen equipment, and USDA processing schedules for vegetables were not widely disseminated to households until the 1910s and after. The mention of a branded "jar holder" as an upgrade over hay is a small reminder that this was a period of brisk trade in canning gadgets sold to women preserving a spring vegetable with a very short season.