Page:A Practical Treatise on Brewing (4th ed.).djvu/231

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SPONTANEOUS FERMENTATION.
215

may be injurious, the proper effects of that extract which has already been so well prepared.


SPONTANEOUS FERMENTATION.

It being a disputed point whether the vinous fermentation would take place, in worts or wash, when the air is excluded, without any addition of yeast or other ferment, we shall here introduce minutes of an experiment, which was made under our notice, and which appears very conclusive. The quantities operated upon were but small, being only two pints of distiller’s wash. One pint at a gravity of 75.2 by Bates’ instrument, was put into a common wine bottle, which was well corked, and a piece of bladder tied tightly over the cork, so as to exclude all extraneous matter: the gravity of the other pint was 41.5 by the same instrument, and was put into another bottle, and treated precisely as above, no yeast was employed. The two bottles were then suspended in a distiller’s wash-back, which had just been pitched at a temperature of 66°, with the usual quantity of yeast.