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.
In addition, this page instructs cracking peach stones and adding the kernels to the preserve. These kernels contain amygdalin, which releases hydrogen cyanide, and should not be eaten.
This information has been left in for historical purposes but should not be acted upon.
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Preserved Peaches
Take some large, juicy peaches, peel and quarter them. Crack half the stones and blanch the kernels. Weigh the peaches, lay them in a deep dish mixing with them the blanched kernels, and one pound of powdered white sugar to every pound of peaches; cover and let them remain all night. Next day put all the contents of the dish into a preserving-pan, and boil them till they look clear, and are quite soft, removing all the scum as it rises. When the fruit is soft and clear, take the pan from the fire, let it cool a little, and then put the preserve into jars. When quite cold lay a piece of white paper dipped in brandy on top of the preserve in each jar, and cover the jars air-tight.
Two separate problems make this preserve unmakeable today: the peach kernels stirred into the fruit, and the sealing method. The notes below explain what each term meant and where the recipe fails.
- The kernels are the main hazardThe seed inside a peach stone contains amygdalin, which releases hydrogen cyanide when the kernel is chewed, crushed or wetted. "Crack half the stones and blanch the kernels" means the almond-like seeds are peeled and left in the preserve as a flavouring, and blanching in hot water does not destroy amygdalin. Half the kernels from a batch of large peaches is not a trace amount, and the recipe gives no fruit weight, so the dose is unknowable.
- Bitter-almond flavour, then and nowNineteenth-century preservers used peach and apricot kernels and bitter almonds for that marzipan note. Commercial almond flavouring today is either synthetic benzaldehyde or is processed from bitter almonds and stone-fruit kernels with the cyanide removed, and so carries none of the risk.
- The seal is not a sealA round of white paper dipped in brandy laid on the surface, then a cover "air-tight," was a standard pre-canning method: high sugar plus surface alcohol plus exclusion of air. It relies on a sugar concentration the recipe never verifies and gives no heat processing of the filled jar at all. Surface moulds and yeasts are the common failure.
- No quantities, no endpoint"Some large, juicy peaches" and "boil them till they look clear" give neither a batch size nor a finishing temperature or set test. Modern preserving depends on both. If you want peach preserves, use a current tested recipe with weights and a water-bath process time.
- Powdered white sugarFor reference: in Oscar's day this meant finely ground granulated sugar, closer to today's caster sugar than to confectioners' sugar, which contains cornstarch. The recipe's pound-for-pound ratio with the fruit is the classic full-sugar preserve proportion.
- Preserving-panA wide, shallow, unlined copper or brass pan, used because the large surface area evaporates water fast. A wide stainless or enamelled pan is the modern equivalent; unlined copper is no longer used for acid fruit.
Oscar Tschirky's 1896 book was assembled at the height of the American preserving era, when a hotel kitchen and a household kitchen are often said to have used essentially the same technique: equal weights of fruit and sugar, an overnight maceration to draw out juice, and a paper-and-brandy cover in place of a processed seal. Mason's screw-top jar had been patented decades earlier, but the science of heat processing did not reach domestic cookbooks in usable form until the U.S. Department of Agriculture and the state extension services began publishing tested times in the early twentieth century. The peach kernels belong to an older tradition still: fruit stones were treated as a free flavouring, and recipes for preserved peaches, apricot jam and ratafia routinely called for a handful of cracked kernels to sharpen the fruit. Cyanogenic glycosides in stone fruit seeds were identified in the nineteenth century, but the practice faded from cookbooks only gradually, and the availability of commercial almond flavouring is often credited with hastening its decline.