117 



THE CHEMICAL COMPOSITION OF CALIFORNIAN WINES. 



BY W. IVISON MACADAM, LECTURER ON CHEMISTY, EDINBURGH. 



Until lately the principal part of the wines obtainable were those 

 grown on the continent of Europe. Within the last few years, how- 

 ever, several new countries have forwarded small consignments to 

 the British market. 



For the proper growth of the wine vine, it is necessary that the 

 climate should not be liable to rapid changes of temperature, for 

 although a hard frost in the winter, when the sap is not ascending, 

 does no damage but rather good to the plant, yet during the spring 

 months the vine must not be exposed to sudden frosts, else the ten- 

 der fruit branches will be liable to be frosted and their proper growth 

 damaged or permanently destroyed. It is also necessary that the 

 vines should not be exposed to heavy rains during the autumn 

 months, as these deteriorate the fruit crop. 



On the continent of America the State of California is particularly 

 adapted to the growth of the vine, for although the temperature is 

 somewhat low during winter, yet the spring, summer, and autumn 

 months may be depended on. For the last few years much attention 

 has been devoted in the State to the growth of the better class of 

 wine vine, and great improvement has been made in the vineyards 

 by the introduction from Europe of plants and graftings of the Ries- 

 sling, Malvoisie, Zinfandel, Orleans, Berger, and other high class 

 varieties. The wines manufactured are large in number and include 

 white and red varieties, ports, champagne, etc. 



Samples of port, malaga, sherry, and a special variety called 

 ''Mount Vineyard," were obtained direct from the American vine- 

 yards, and submitted to analysis, when they gave the following- 

 results : 



Port. 



Specific gravity of wine 1022.96 



Specific gravity of wine, minus alcohol 1035.03 



Specific gravity of distillate 977.01 



Percentage of alcohol by weight 15.99 



Percentage of alcohol by volume 19.00 



In One Imperial Gallon. 



Total dry residue 8439.90 grains. 



Total dry residue, minus ash 8194.90 grains. 



Total ash 245.00 grains. 



Crape sugar 5833.00 grains. 



Fixed acid, calculated as tartaric acid 249.90 grains. 



Volatile acid, calculated as acetic acid 42.00 grains. 



In One Hundred Parts. 



Dry residue 11.786 grains. 



Dry residue, minus ash 11.444 grains. 



Ash 0.342 grains. 



Grape su<*ar 8.146 grains. 



Fixed acid, calculated as tartaric acid 0.357 grains. 



Volatile acid, calculated as acetic acid 0.060 grains. 



Taste, sweet. 



Color, rich. 



