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THE CLOUDING OF WHITE WINE. 



By R. Greig Smith, M.Sc, Macleay Bacteriologist to the 

 Society. 



Under the name of Chablis there is made in South Australia 

 a variety of white wine which has a great tendency to develop a 

 turbidity or cloudiness soon after it is bottled. It is a soft wine, 

 and in consequence of the low acidity the feraientation is pro- 

 longed while a trace of sugar is left unfermented. In the 750 

 gallon storage casks, and in the smaller 100 gallon casks 

 from which it is bottled the wine is absolutely brilliant. 

 It is also perfectly bright immediately after bottling, but 

 after an interval of some days or weeks — depending upon the 

 air-temperature — the brilliancy disappears and the wine slowly 

 becomes dull and then clouded. When undisturbed a deposit 

 collects at the bottom of the bottle, and the wine becomes less 

 clouded; a shake is, however, sufficient to disturb the sediment' 

 and distribute it throughout the wine. The change seems to 

 have no effect upon the composition of the wine, for the flavour 

 and bouquet remain unaltered. The trouble is of considerable 

 importance to the wine industry, as many thousands of bottles 

 may be annually rendered commercially useless, since the public- 

 will not buy a turbid wine, even although the wine is otherwise 

 excellent. 



At my request a sample bottle of wine was sent to the laboratory. 

 It arrived in perfectly bright condition, but during the course of 

 a fortnight it became dull and finally turbid. An investigation 

 was started to determine the cause of the phenomenon. Obviously 

 the first thing to be done was to grow any living organisms that 

 might be in the wine, then having obtained them in pure condition 

 to infect healthy wine, and so prove a particular organism as the 



