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CHAPTER VII. 



Neav Prookss for the Manufacture of Beer. 



The principles established in the course of this work implicitly 

 involve the conditions of a new process of manufacture, the 

 essential feature of which would consist in the production of a 

 beer of excellent keeping qualities, we might even say a beer 

 that could not undergo alteration. It will not be difficult now 

 to make ourselves clear on the point. 



We have shown in the first place, that the changes which 

 take place in the ferment, the wort, and the beer itself, are 

 due to the presence of microscopic organisms of an entirely 

 different character to that of the ferment-cells properly so 

 called, which organisms, by simultaneously giving rise, in the 

 course of their multiplication in the wort, ferment, or beer, to 

 other products, make the materials difficult to keep or effect 

 their deterioration. Again, we have seen that these change- 

 producing organisms, the ferments of disease, never arise 

 spontaneously in the wort or beer, but, whenever they make 

 their appearance in these fluids, have been imported from 

 without, either in company with the yeast, or from accession of 

 atmospheric dust, or from contact with the vessels, or from the 

 materials themselves which the brewer uses in his manufacture. 

 Moreover, we know that these disease-ferments, or their germs, 

 are destroyed when the wort has its temperature raised to the 

 boiling-point. And, following up the inferences from such 

 facts, we have seen that wort exposed to pure air, after having 



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