24 Journal of Agriciiltitre , Victoria. [lo Jan., 191 i. 



How THE Method Became Popular. 



It i.s rather surprising that the general use of sulphurous acid did not 

 long ago become popular. The method of white wine-making, known 

 in French as debourbage (literally, remo\al of mud), has long been 

 known and differs but slightly from the one under review. The former 

 has, however, only been applied to white wines, whereas the latter is 

 ■equally applicable to red or to white. 



A description of debourbage or setting, will be found in the transla- 

 tion of Roos' Wine -making in Hot Climates (issued by this Department) 

 p. 169. Briefly, it consists in delaying the start of fermentation for a 

 day or two, during which time a sediment, consisting of impurities, 

 albuminous matters, &c., is allowed to deposit. The clear juice after 

 being run off from this sediment is fermented apart, the resulting wine 

 being cleaner and, especially, better in condition than that fermented in 

 the ordinary way, without preliminary separation of impurities. In the 

 case of debourbage, the delay in the start of fermentation is obtained 

 by treatment with sulphur dioxide produced by burning sulphur. 

 According to Roos, the dose necessary to delay its commencement foi 

 18 to 24 hours is .05 grammes per litre of must (f oz. per 100 gallons). 



Numerous writers have, within the past few years, recommended the freer 

 use of sulphurous acid in wine-making, but to MM. Dupont and Ventre, 

 of the Montpellier' School, is due the credit of having brought the use 

 of this well known substance into every day practice. Their experi- 

 ments in connexion with it have covered a period of about seven years. 

 The articles they have published,* especiallv tlie first one in 1906, have 

 drawn public attention to the advantages to be obtained ; advantages 

 which have impressed themselves so forciblv on all those who ha\'e tried 

 it, as to have led to the astonishing increase in its general application 

 referred to above. 



For the greater part of the information which follows I am indebted 

 to the articles of MM. Dupont and Ventre. 



Action of Sulphurous Acid. 



This exerts itself in several ways, but mainly through its antiseptic 

 action on the different micro-organizms contained in the fermenting mass. 

 It has long been known that most of the wdne-maker's troubles are due 

 to the development of bacteria. Even defects which only make their 

 appearance months afterwards, are indirectly due to bacterial actio- 

 during the first fermentation, the presence of which may not even have 

 teen suspected at the time. The mannitic ferment is, in this way, 

 one of the greatest enemies the wine-maker has to contend against in 

 Northern Victoria. This antiseptic action of sulphurous acid is more 

 severely felt by injurious bacteria than by yeasts. Its presence in the 

 fermenting mass prevents the development of the former, whilst it only 

 slightly retards, and that only at the commencement of fermentation, 

 that of the latter, which are thus permitted to do their work freelv and 

 without hindrance, and consequently under the best possible conditions. 



Bacteria, though the most dangerous competitors of the alcoholic 

 ferment, are not its only opponents. There are many varieties of 

 alcoholic ferment ; some of these, usually known as wild yeasts, are 

 little less objectionable than bacteria. Sulphurous acid hinders the de- 

 Tel opment of these wdld yeasts more than that of the true wine ferment 

 ■{Sac char am yes ellipsoid ens). \n the words of M. Dupont — 



The different sensitiveness of the various orc;anisms in the crushefl grapes, and 

 •especially of the different kinds of alcoholic veasts, has, as a fortunate consequence, 

 a veritable natural selection in favour of the elliptical yeast, the most resistant 

 ■and the most useful of all. 



* E. Dupont and .T. Ventie, L'acide Sulfiu-eux en Vinification, Progres Agricole, 1906-7-8, &c. 



