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Rhubarb (Select stalks of choice)
Select stalks of choice rhubarb that has been quickly grown. A barrel from which the heads have been taken, set over a bunch of well-enriched rhubarb, will occasion very tender stalks. Wash and wipe the stalks, but do not remove the skin. Cut the stalks to the height of the jar below the neck, fit in as many as the sterilized jar will conveniently take, then fill the jar to overflow with cold water; adjust a new rubber and the cover and set aside in a cool place. Rhubarb No. 2 Set the sterilized jars just as they are filled with boiling water at one side to cool, then empty out the water and fill to overflow with cold water from the faucet. Have ready stalks of rhubarb cut into pieces about an inch in length, drop these into the jars, shaking them down meanwhile until no more can be put into them, and leave space for at least half an inch of water above; add more cold water, adjust the rubber rings, and sterile covers, tighten the covers, and store in a cool, dry, dark place.
Both versions here are "cold water canning" — rhubarb packed raw into jars, covered with tap water, sealed and set aside with no heat processing at any stage. The terms are worth explaining, but the method is not one to follow.
- No thermal process at allNothing in either version brings the packed jar to a temperature that destroys spoilage organisms. Pouring boiling water into an empty jar and tipping it out treats the glass, not the food, and the cold faucet water added afterwards reintroduces whatever the tap carries. Modern practice processes rhubarb in a boiling-water canner for a measured time, and no time or temperature appears here.
- No vacuum, so no reliable sealA safe seal in a screw-top jar is produced by hot contents contracting as they cool and pulling the lid down. A cold-packed, cold-filled jar never develops that vacuum, so the closure depends entirely on the rubber ring staying compressed. Failures show up as cloudiness, gas, and surface mould weeks later.
- Acidity limits one risk but not the othersRhubarb is genuinely acid — typically around pH 3.2 — which is why generations of households got away with this and why Clostridium botulinum is not the main concern. Yeasts, moulds and lactic bacteria are entirely comfortable at that pH, and mould growth in a sealed jar can raise the pH of the surrounding food over time. Use a current tested recipe instead.
- "A new rubber"Jars of this period sealed with a flat rubber gasket between jar shoulder and glass or zinc lid. The instruction to use a new one each time is sound; a reused, hardened ring was a common point of failure. The modern two-piece lid with its bonded sealing compound is the direct descendant, and its flat disc is likewise single-use.
- The barrel over the rhubarbSetting a headless barrel over a crown forces the stalks upward in darkness, producing the pale, slender, very tender rhubarb that forcing pots were made for. It is a horticultural instruction, not a kitchen one, and has no bearing on preservation.
- Leaves are not mentioned, and should not beOnly the stalk is used. Rhubarb leaves contain oxalic acid and related compounds at levels that make them unfit to eat; recipes of this period generally speak of stalks alone.
Cold water canning of rhubarb appears in early twentieth-century preserving manuals, and it survived precisely because rhubarb is so acid that the results were usually merely disappointing rather than dangerous. The appeal was obvious in a household without refrigeration: rhubarb comes in a rush in spring, sours nobody's patience faster than a glut, and here was a way to hold it for winter pies without sugar, fuel, or a long afternoon at the stove. The instruction to leave the skin on reflects the same economy. Extension bulletins are generally said to have discouraged open-kettle and cold-pack-without-processing methods from about this period, and the technique disappeared from official guidance well before it disappeared from family notebooks.