246 PRESENT POSITION OF 



in Australia were likewise opposed to the objections raised 

 in England. It is here worthy of note that the methods 

 adopted in the Australian breweries were essentially the 

 same as in England. As there appeared to be an inclination to 

 experiment with a mixture of yeasts, I showed how this could 

 be carried out. In this case, also, pure culture and systematic 

 selection of the distinct species is, of course, necessary if 

 certainty is to be secured. But since this would present great 

 difficulties in breweries, I advised against the employment 

 of mixtures, and recommended experimenting with single 

 species according to the methods which I had elaborated. 



The reasons for adopting the new system are the same 

 in the case of the English high-fermentation breweries as in 

 the other branches of the fermentation industry. The fer- 

 mentations in English breweries are, as elsewhere, exposed 

 to the danger of attack by bacteria and wild yeasts, which 

 may cause sickness in the beer, and thus give rise to great 

 disturbances and heavy loss. English brewery yeast, more- 

 over, usually contains not one, but several culture species ; 

 there is no certainty at all that the most favourable species 

 preponderates, and it is not even certain that it is present at all. 

 Everything depends here on chance ; the brewer knows really 

 nothing about the yeast which he puts into his fermenting 

 vessels. 



In many of the old breweries in England, which I had 

 an opportunity of visiting, the fermenting rooms were badly 

 arranged, and for want of space these could not be improved. 

 Dust could enter freely, and every current of air brought 

 infection with it. Under such conditions, it is especially de- 

 sirable to introduce large quantities of a satisfactory species in 

 pure culture throughout the brewery. By this means, bot/i 

 bacteria and ivild yeasts are suppressed in the most effective 

 manner. If it is not possible to introduce pure culture 

 entirely, we still have it in our power to maintain a pre- 

 ponderance of the desired species. 



