The book of fruit bottling / by Edith Bradley and May Crooke. A practical manual on the process of fruit bottling. Jams, jellies, and marmalade making: chapters on fruit drying, home-made wines and cider making, with preface urging upon county councils the importance of fostering these industries in rural districts. Introduction by Rev. W. Wilkes.

  • Bradley, Edith.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The book of fruit bottling / by Edith Bradley and May Crooke. A practical manual on the process of fruit bottling. Jams, jellies, and marmalade making: chapters on fruit drying, home-made wines and cider making, with preface urging upon county councils the importance of fostering these industries in rural districts. Introduction by Rev. W. Wilkes. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    exact degree of heat required to destroy the germs varies considerably according to the object which is being sterilised; in fact, some fruits and some vegetables, require three or four successive sterilisations (by which first one bacteriological family and then another are destroyed) to bring about the required conditions. The hot air and steam by which the bottles in the steriliser or other vessel are now surrounded causes the water or juice inside the bottles to get hot and expand until it reaches the air-tight capsule or cover. The requisite temperature is sustained for some time at an equal height until the process is complete (this can be determined to a nicety by the fixed thermometer), and the bottles are either lifted out and put into a cool place, or else cold water is turned into the machine whilst the bottles are in it (the hot water having been previously drawn off). With the decreasing temperature a vacuum is created, and unless the caps or tops are imperfect or imperfectly adjusted, and so admit the air, the contents of the jar, as before stated, will keep for any length of time, because germs do not incubate in a vacuum. This, then, is the theory carried out by the process of sterilisa- tion. If sufficiently complete—and, as before stated, the requisite temperatures for the different fruits and vegetables have been proved, and these temperatures are registered by a thermometer—the vacuum is attained and the germs made sterile. It may chance, however, that the rubber bands or the caps are not placed on the bottles quite evenly, or if the cap is screwed that the screw ring is not quite perfect, then, if from one cause or another air is admitted, as a certain consequence the vacuum is destroyed, the germs come into life, and immediately begin to cause decay and decomposition or fermentation. If this is not at once noted, and the batch of bottled fruit re-sterilised and re-capped, it will all go bad, and very bad too, especially in the case of