100 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



necessity of judging of the purity of commercial samples made iu 

 different ways and with admixtures of various kinds has resulted a 

 general study of authentic maple products gathered from all of the 

 important centers of production in this country and in Canada. A 

 study of methods of manufacture accomy^anicd the analytical exami- 

 nation of the 481 samples obtained, thus furnishing reliable data for 

 judging of the qualit}' of this product whatever its source might be. 

 Previous work on this subject has covered only limited areas or 

 localities. The results indicate that methods of manufacture influ- 

 ence the variations in color and flavor of the finished product to a 

 greater extent than does the environment. 



Vinegar. — The many cases arising in regard to sophisticated 

 vinegars, especially those in which inferior products are labeled as 

 cider vinegar, has led to a thorough investigation of tliis industry. 

 Authentic samples were obtained for study at a number of factories 

 throughout the Eastern and Central States, where every stage of the 

 operations could be observed and data established in regard to the 

 progressive composition of the product. In this way such sophisti- 

 cations as the use of vinegar made from apple wastes, dried skins, 

 and cores, or the admixture of pomace and second-pressing vinegars 

 with pure-cider vinegar, or their dilution with grain or white-cider 

 vinegar or with boiled cider may be detected by comparison with 

 the standard data. The results obtained have alread}^ been of great 

 value and have made it possible to interpret more intelligently the 

 analytical results obtained in the examination of unknown samples. 



Miscellaneous fruit products. — A large number of studies were 

 made in cooperation between the Pomologist of the Bureau of Plant 

 Industry and the Bureau of Chemistry looking to the development 

 of new fruit products, the improvement of present processes, and the 

 more profitable utilization of certain crops. Among these are inves- 

 tigations of the yields obtained by different methods of producing 

 grape juice; the effect of storage at low temperatures on sweet ciders, 

 showing that it may be held from six weeks to three months at 32° F. 

 before fermentation begins, that it ferments very slowly and retains 

 its flavor well if withdra\\Ti and held at refrigerator temperature; 

 a successful attempt to produce a marketable vinegar from peaches; 

 the production of a ver}^ palatable product by drying and sugaring 

 pineapples; a study of the practice of picking immature oranges and 

 grape fruit and sweating them to produce quick ripening which showed 

 that the product was very inferior and if followed might injure the 

 industry; and a study of the production of citrus by-products in 

 California, together with the examination of authentic samples of 

 Sicilian citrus oils. 



Extensive enological investigations were conducted at Charlottes- 

 ville, Va., with a temporary laboratory in the grape belt of northern 



