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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PEAS, GREEN, PRESERVED (other ways)
Fill a tin box with them, pour in a little water which has been salted, put on the cover, which must be soldered, so that the box shall be hermetically tight, and then boil the box. Or, dry the peas in a cool oven, and afterwards hang them up in paper bags. Or, gather the peas on a fine dry day, open the pods on a large clean cloth, and leave the peas for five or six hours exposed to the sun and air. Rub them gently in a rough towel till they are perfectly dry, bottle them as air-tight as possible, and store in a dry place.
Three methods are given here: one is sealed canning, and it is the reason this page carries a warning. The other two are air-drying, which is the older practice the canning was meant to replace.
- Why the tin-box method failsGreen peas are a low-acid vegetable, around pH 6.2, which is exactly the range in which Clostridium botulinum spores can germinate in a sealed, oxygen-free container. Boiling water tops out at 212F, well below the temperature needed to destroy those spores, so a hermetically sealed box of peas simmered in a pot is an incubator rather than a sterilised pack.
- No time is given at allThe instruction is simply "boil the box." There is no processing time, no headspace, no jar size and no measure of salt. Even setting the pathogen aside, nothing here can be checked or repeated, which is the minimum a preserving recipe has to offer.
- Soldered seamsSealing a food tin with solder at home is described in period sources, and solder of the era was lead-based. Lead migrates readily into wet, salted food. Modern home canning uses glass jars with two-piece lids for this reason among others.
- Salt does nothing useful here"A little water which has been salted" is far too weak a brine to inhibit anything. Salt only suppresses bacterial growth at concentrations high enough to cure, and this is seasoning, not preservation.
- The drying methods rest on a different principleSun- and oven-drying work by removing water rather than by sealing, and dried peas were a staple of British larders for centuries. But "perfectly dry" is a judgement, not a specification, and peas bottled while still faintly damp will mould in the jar.
- If you want to put peas byUse a current USDA or equivalent guideline for pressure canning, or simply freeze them. Blanched green peas freeze extremely well and lose almost nothing that this page was trying to save.
Cassell's is writing in the decades when domestic canning was new enough to be exciting and not yet understood well enough to be safe. Nicolas Appert's sealed-jar experiments in France, published in 1810, and the tinplate patents that followed in Britain gave households the idea that heat plus an airtight seal equalled indefinite keeping — a rule that holds for acidic fruit and fails badly for peas, beans and corn. That the connection between improperly canned low-acid food and botulism was not established until the early twentieth century explains why a book of this era could print "boil the box" with no further detail and no sense of risk. The two drying methods printed alongside are much older, and much closer to what a country household would actually have done: peas shelled onto a cloth, sunned, rubbed dry in a towel and bottled.