68 MICRO-ORGANISMS AND FERMENTATION. 



After a thorough examination Hansen came to the conclusion 

 that, without doubt, scarcely a single organism which entered 

 the flasks proceeded from the grains. The result tends 

 to show that in this, as in other cases, air does not take up 

 organisms from moist surfaces. 



This, however, must not be misunderstood to mean that 

 grains may be allowed to accumulate, without risk, and that 

 after removal, the residue may be exposed to the weather. It 

 is clear that this would constitute a great danger. When the 

 remains become dry and are blown about in the air as dust, 

 masses of bacterial germs will be carried up at the same time, 

 and will, without doubt, constitute a source of frequent bacterial 

 contamination. For this reason, places where grains have 

 remained for any length of time must be washed with lime- 

 water or, preferably, with chloride of lime.* 



In a corridor which led to a room where the barley was 

 turned, the flasks always received a greater contamination 

 than anywhere else ; bacteria especially were found in them 

 in great abundance. 



On the malt floors the condition of the air was also charac- 

 teristic ; it always contained a very strong contingent of mould 

 spores. In the case in question these consisted of Eurotium 

 aspergillus, which was otherwise rare. On the malt itself, 

 as usual, Penicillium glaucum occurred most frequently. 



The greatest interest, however, attaches to the examination 

 of the different fermenting-rooms, partly in the " Old Carlsberg " 

 brewery and partly in the brewery " N." In the former 

 the air contained fewer organisms than in any of the rooms 

 examined during the whole research ; in the fermenting- 

 cellars of the brewery " N," on the contrary, a large number 

 of flasks (55, 75 to 100 per cent.) were infected. The organisms 

 which occurred in the air of these cellars were Saccharo- 

 myces cerevisice, Mycoderma cerevisice, S. Pastorianus, S. 

 ettipsoideus, Torula, and other yeast-like cells ; further, 

 Penicillium, Dematium, Cladosporium, and rod bacteria. 



* The germs are not killed during the treatment of the grain in drying machines. 

 Such forms of apparatus, therefore, constitute a very great danger in the brewery, 

 since dust-clouds of bacteria may be transported from the dried grains to the 

 open coolers or into the fermentation vessels. 



