213 



THE LOSS OF COLOUR IN RED WINES. 



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



Society. 



Two samples of red wine were obtained from a correspondent 

 in South Australia, who gave me the following historj' of them: — 



Sample A. — A dry red wine, 1900 vintage. It kept in good 

 condition and order until April, 1903. In the cask it remained 

 without much apparent change of condition. Upon removing a 

 sample from the cask and exposing it to the air, it became per- 

 ceptibly dull and threw down a copious black powdery deposit, 

 which increased up to a certain limit. The wine then commenced 

 to clear again. The wine contained short rod-like bacteria which, 

 after exposure to the air, as detailed above, became fringed with 

 debris. 



Sample B. — A dry red wine, 1901 vintage. This wine appears 

 to have been infected in bulk with the organisms of "vm tourne.^^ 

 It behaved like Sample A, but not to the same extent. 



The bacteriological examinations of both samples showed that 

 they contained a few moulds, Penicillium, glaucum, and a great 

 number of short rod-shaped bacteria, which grew very slowly 

 upon nutrient glucose-gelatine, glucose-yeast-water-gelatine and 

 alcohol (5%)-yeast-water-gelatine. The colonies grew slowly and 

 were always punctiform and microscopically circular and finely 

 granular. In stroke culture upon the various gelatine media they 

 grew slowly as a white narrow line, and did not liquefy the 

 gelatine. 



Small experimental flasks of an Australian claret were infected 

 with the bacterium and placed in the incubator at 22°. In five 

 days the wine had lost its brightness, while a slight film and 

 sediment had formed. By the tenth day the wine had become 

 decidedly lighter in colour; the film had become stronger and the 



