308 PROCE'EDINGS OF SECTION B. 



of Germany and France. The acidity is also lower, and though 

 not much lower absolutely it is much lower in relation to equal 

 quantities of sugar. In determining the relation to these sugar 

 strengtlis of musts to the alcoholic strength of * the resulting wines, 

 on the supposition that all the sugar is fermented, we can use 

 Pasteur's result (Annales de Chimie et de Physique, 3rd ser. 58, p. 

 330), that the sugar gives half its weight of alcohol. Accordingly 

 our average Victorian must of 1893 would, if completely fermented, 

 give a wine containing 12-8 grammes of alcohol per IdO e.c, 

 while the average alcoholic strength of Victorian wines previously- 

 given by me is nearly 12 grammes of alcohol per 100 c.c. Thus it 

 appears that the high sugar strength of Australian musts explains 

 the high alcoholic strength of Australian wines. When the same 

 comparison is made for French and German musts and wines there 

 is the same agreement ; thus, the average German must, were all its 

 sugar fermented, would give a wine containing 8*5 grammes of 

 alcohol per 100 c.c, the actual average strength of German wines 

 being 7"6 grammes per 100 c.c. ; similarly with the French. 



It is obvious that if Australian wines are to be brought nearer 

 to the French and German standard the musts must be lowered in 

 sugar content and raised in acidity. As to definite methods of 

 achieving these desirable ends, special practical experiments in 

 cultivation and in accurate timing of the vintage seem io be 

 required. Apparently it is almost uniformly the practice in 

 Vict(jria to allow the grapes to becoiue over-ripe before gathering. 

 It ought to be possible on each vineyard to determine a point in 

 the ripening at which sugar and acid stand nearly in the pro- 

 portion characteristic of French and German musts. By reducing 

 the sugar strength the alcoholic strength of the resulting wine will 

 be reduced, and by increasing the acid the material will be 

 proA'ided for the formation of those ethers which are regarded as 

 giving the higher qualities to a wine. In connection with this it 

 is interesting to know that as long ago as 1851 the great Liebig 

 (Letters on Chemistry, 3rd ed.) says, "The free acids which are 

 present in fermenting juice take a most decided part in the 

 formation of those aromatic matters upon which odor and flavor 

 depend. T'he wines of southern regions are produced from 

 perfectly ripe grapes; they contain tartar, but no free organic 

 acids ; they scarcely possess the characteristic odor of wine, and 

 with respect to bouquet or flavor they cannot bear a comparison 

 with the nobler French or Rhenish wines." 



Associated with the question of sugar strength, tliere is an interest- 

 ing result of, receipt researches on the sugars, that the sugar in grapes- 

 is a mixture of dextrose and levulose, the latter preponderating in 

 over-ripe grapes and the former in unripe (Mach & I'ortele, Bied. 

 Centr. Blatt., 1881 .; Jour. Chem. Soc. Abstr., 1881, p. lOGi;, and 

 ks levulose. is iesis fermentable than dextrose (Dubrunfaut, I'ortes 

 aiid Kuj-ssen, vol. ii., p. 214; Borntriiger, Zeit. fiir ang. Cheau€y 



