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 Rhubarb
Remove the skin from the rhubarb and cut the plant into inch lengths. Pack it closely in glass jars, fill the jars to overflowing with cold water and screw the top on tightly. Invert the jar to disclose any leak. If the jar is perfect, this canning, simple as it is, will be successful; if the jar is not air-tight it will not be.
The vegetable is delicious for pies in the winter. No cooking is required for the preservation of the plant.
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This is cold-water canning: raw rhubarb, plain water, no heat at any stage. It was a widespread household practice and it survives in family notebooks, but it is not a process any current authority endorses, and the reasons are worth understanding.
- Nothing here is processedThe jar is never heated, so nothing is sterilized and no vacuum ever forms. The seal depends entirely on a hand-tightened lid holding against whatever grows inside, which is why the recipe frets so much about whether the jar is "perfect." A screw band tightened by hand is not a substitute for a heat-set seal.
- Acidity is not a complete defenseRhubarb is genuinely high in acid, usually around pH 3.1 to 3.4, which does suppress Clostridium botulinum. What it does not suppress is the mold, yeast and lactic bacteria that thrive in cool acid water, and molds growing on the surface can raise local pH enough to open the door for worse. A low botulism risk in a raw rhubarb jar is not the same as safety.
- The water is the problem, not the rhubarbCold tap water carries its own microbial load into a container that will sit closed for months at room temperature. Current rhubarb canning recipes heat the fruit and the liquid and then process the filled jars in a boiling-water bath for a measured time.
- Leaves must never go inOnly the stalks are used. Rhubarb leaves and leaf tops contain oxalic acid and related compounds at levels that cause serious poisoning, and they were a documented cause of illness during the First World War when they were promoted as a green vegetable.
- "Screw the top on tightly" meant something elseIn 1911 this would most likely have meant a zinc cap over a rubber ring on a Mason jar, though other closures were in use. Modern two-piece lids are designed to vent during heating and seal as the jar cools; fastening one down tight on a cold raw pack gives you a closed container, not a sealed one.
- If you want winter rhubarbFreezing raw cut stalks is the direct modern equivalent of what this recipe was trying to achieve, and it holds the texture better for pies. For shelf-stable jars, use a current USDA or extension-service rhubarb recipe with a specified processing time.
Rhubarb was known in America as pie plant, and for most of the nineteenth century it was among the first edible things out of the ground after a long winter of root vegetables and dried fruit, arriving weeks before any berry. That scarcity helps explain why a book like the Butterick Cook Book, published for the readers of a pattern and fashion publisher and aimed squarely at ordinary housekeeping, gives space to a method this thin: cold-water canning of rhubarb appears to have circulated as household practice rather than as tested procedure, and the plant's own acidity would have made it succeed often enough to seem reliable. The confident claim that "no cooking is required" belongs to a period when spoilage was widely understood as a matter of keeping air out rather than killing what was already in the jar; the germ theory of fermentation was decades old by 1911, but the specific bacteriology of home canning, and the identification of botulism in commercially and domestically packed foods, was still being worked out in the years that followed.