234 ON THE PRESENCE OF FUSEL OIL IN BEER. 



The next step is to l>oil the wort in a separate vessel termed 

 the copper, together with a certain quantity of hops. The object 

 of adding the hops is to impart the well-known bitter flavour — to 

 endow the beer with narcotic properties, and finally to act as a 

 preservative agent and so enhance the keeping qualities of the 

 beer.* After boiling, the worts are rapidly cooled clown to a 

 temperature, varying from 58° to 62° Fall., and run into the 

 fermenting " rounds " or " squares " Yeast is now added — or in 

 the language of the brewer — fermentation is said to be '• pitched " 

 at a temperature varying with the locality, and the practice and 

 ideas of the brewer. 



Fermentation proceeds rapidly attended by a rise in temperature; 

 and here comes one of the most critical parts of the process of 

 brewing. It is after the worts have arrived at the fermenting 

 tuns that the brewer's skill and experience conies in. I do not 

 mean that any amount of skill in regulating the fermentation will 

 ever remedy carelessness in mashing, because, if the wort is not 

 perfectly sound on its arrival at the fermenting tuns, a perfect 

 fermentation cannot be obtained ; but only that, be they ever so 

 satisfactory at this point, negligence or unskilfulness will be then 

 even more fatal than at any other previous stage. Here it is that 

 with a climate like that of Sydney, ice or artificial cooling machinery 

 becomes absolutely essential for the production of good beer. 

 Experience has shown, that fermentation should never exceed 70° 

 to 72° Fah. When this temperature is exceeded no amount of 

 after treatment or doctoring of the beer will ever remove its own 

 inherent bad quality. f 



What goes on in the act of fermentation will be better understood 

 if we regard the wort merely as a sugar solution with some other 

 albuminous bodies that may be more conveniently considered 

 hereafter. 



Alcoholic fermentation is the outcome of the life of a minute 

 plant — a very lowly organism called the yeast cell or Saccliaromyces 

 ■cerevisirv. The sugar solution is its arena, and ethylic alcohol is 

 one of the products of its own life-decomposition, just as much as 

 urea is one of the life-products of a man. As plants possess the 

 faculty of changing the carbon dioxide of the atmosphere into 

 starch, sugar, alkaloids and other products, so this little cryptogam 

 lives upon the maltose of the brewer's wort changing it into alcohol 

 and other compounds. 



* Hops are to the high fermentation brewer what ice is to the brewer 

 of lager bier. 



f Pasteur speaks of this as " a rigorous limit of fermentation tempera- 

 ture." " Etude sur la Biere/' Paris 1876, p. 14. 



