48 COMPOSITION OF AMERICAN WINES. 



The percentage of alcohol is not as important as certain ratios 

 between alcohol and other constituents. 



GLYCEROL. 



The amount of glycerol ordinarily present varies between 0.40 gram 

 and 1 gram per 100 cc. In the records of the Weinstatistik Commis- 

 sion pure wines are noted whose glycerol content is between 0.20 and 

 1.39 grams per 100 cc, but cases which do not come within the first- 

 named limits are very rare. Unfortunately this determination is one 

 which has seldom been made on American wines. In those recorded 

 herein the lowest glycerol content is .163 and the highest 1.083 

 grams. 



GLYCEROL-ALCOHOL RATIO. 



The glycerol-alcohol ratio is considered of great importance in judg- 

 ing of the purity of a wine. The German Weinstatistik Commission 

 decided in 1884 that in pure wines the glycerol-alcohol ratio might 

 vary between T and 14 parts by weight of the former to 100 parts of 

 the latter. It is now quite generally admitted that the German wines 

 are not all included within these limits and that the minimum limit 

 should be reduced to 6 parts of glycerol to 100 parts of alcohol. 



The glycerol-alcohol ratio of American wines seems to be much 

 lower than that of wines of European origin. If we were to take 6 

 of the former to 100 of the latter as the minimum, in the analyses 

 which have been made, a large number of pure wines would be 

 condemned. 



While no conclusions should be drawn until more work has been 

 done on this subject, and many analyses have been made of wines 

 manufactured under known conditions, it seems that a much lower 

 glycerol-alcohol ratio will be found to be necessary. 



SUGAR-FREE EXTRACT. 



The sugar-free extract is found by subtracting the sugar present, in 

 excess of 0.1 gram per 100 cc from the total extract as determined by 

 evaporation. In the case of plastered wines the potassium sulphate in 

 excess of 0.1 gram per 100 cc is also deducted. The German Wein- 

 statistik Commission has found that wine made from the juice of ripe 

 grapes rarely contains less than 1.5 grams of extract per 100 cc, and 

 that figure has been adopted as the lowest limit for the German wines. 

 At a recent meeting of the Weinstatistik Commission it was held that 

 the above limit was too low, and the commission seriously considered 

 the advisability of changing the limit to 1.6 grams per 100 cc for white 

 wines and 1.8 grams per 100 cc for red wines. It is necessary that 

 somewhat wider limits should be adopted for American wines. 



