10 ENOLOGK'AL STUDIKS. 



TESTS AND ANALYSES MADE. 



Each sample of juice was then tested as to density with a 

 Brix spindle, and in most instances a sample was saved for further 

 examination. These samples for the year 1908 were bottled and 

 preserved with mercuric chlorid, using tablets purchased at the drug 

 store, and in this condition they were sent to Stonehenge labora- 

 tory, Charlottesville, Va., for analysis. The final analyses were 

 completed by January 5, 1909, and covered only specific gravity, 

 total solids, sugar-free solids, total sugar, and fixed, volatile, and 

 total acid. These data were carefully checked, and in the acid de- 

 terminations allowance was made for the use of the mercuric chlorid 

 tablets, each of which contained 0.5 gram of mercuric chlorid and 0.57 

 gram of ammonium chlorid. One tablet was used for 400 cc of fresh 

 juice. A correction to allow for the acid present in the tablet was 

 made by deducting 0.075 gram tartaric acid per 100 cc of sample. 

 Volatile acid was determined on the samples taken in 1908, but the 

 amount was so slight that it is not reported in the tables; seldom 

 was 0.01 gram per 100 cc of sample found. During the years 1909 

 and 1910 volatile acid determinations were not made. 



The results on total acid for the samples taken in 1908 are sur- 

 prisingly low. This was noted as the samples were analyzed, and the 

 work was carefully checked. The only explanation which is suggested 

 is that during the first season the samples were not pressed sufficiently 

 to bring out all the acid present. It will be readily understood that 

 for red wines the acid content secured by crushing and pressing the 

 fresh fruit will not be the total acid secured by the fermentation of 

 the pulp and then pressing by power, as is customary in the wineries, 

 but for white wine the result should be practically the same as when 

 the fruit is crushed and pressed by power. These points will be 

 covered and the data given in an additional report on the fermenta- 

 tion experiments conducted at the Sandusky laboratory. 



The preparation of the samples during the years 1909 and 1910 

 was uniformly by hand as just described; but, having equipped a field 

 laboratory at Sandusky, the analyses of the juice were made there at 

 once, as far as possible. In every case the acid was determined by 

 the titration of the freshly pressed and filtered juice, and a gravity 

 reading was made on unfiltered juice at the same time, using a Brix 

 spindle specially made for this work. When the analysis could not 

 be made promptly a sample was preserved in a pint champagne 

 bottle with 0.2 gram of mercuric chlorid. The full analysis was 

 completed usually within from 30 to 60 days after sampling. If the 

 presence of sucrose was suspected the analysis was made at once, be- 

 cause experience showed that inversion of this form of sugar occurred 

 even in the chemically preserved sample. 



