CAPE WINE-LEVURES. 



133 



which is very high indeed. It must be borne in mind that must 

 cenologists in Europe are of opinion that wines with over 15 

 volume per cent, alcohol are fortified, since they maintain that a 

 natural wine cannot have over 15 volume per cent, alcohol. In 

 fact the Swiss law on the importation of wines regards all wines 

 f above 15 volume per cent, alcohol as fortified. 



From my cellar experiments with these levures it will be 

 seen that they can on a large scale form wines of over 15 volume 

 per cent, alcohol, which are absolutely natural and unfortified. 



(2) That the calculated alcohol-values, in case of the 13 

 proper wine-levures and with the exception of HeAi, PBi and 



GBi. which formed under 15 volume per cent, alcohol, differ 

 from the actually found values by 0.49 volume per cent, alcohol 

 (on an average). Since some of the carbon dioxide formed by 

 fermentation is dissolved in the wine and has replaced the air 

 in the flask, it must be expected, that the calculated value for the 

 alcohol will be less than that found by analysis. Here it is 

 assumed that the loss of each flask represents the weight of 

 carbon dioxide formed by fermentation less that still in the 

 flask, it being assumed that no other gas is evolved. This is 

 quite a safe assumption to make, since the strong sulphuric acid 

 in the fermentation tube will dry the gas as it escapes, so that n< 

 moisture will be lost, and since no other gas than carbon dioxide 

 is known to be formed during the vinous fermentation, the dry 

 carbon dioxide gas above the sulphuric acid in the fermentation 

 tube and the way it is partly cut off from the air by its glass 

 capsule will prevent any noticeable quantity of watervapour 

 from the air being absorbed. 



