174 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



tion in the storage containers and could be withdrawn in clear con- 

 dition. Tile slatenionts in n.'<;ard to tlie apple juices just made apply 

 equally to the rcnuiining 42 samples of grape juices. It was there- 

 fore clear that satisfactory and generally applicable methods of 

 clarifying these juices must be Avorked out before any effective at- 

 tack upon the problem of blending to produce desirable beverage 

 juices could be made. 



Many different methods of treatment have been tried, the most of 

 which are objectionable for one reason or another. However, it has 

 been found that by the use of infusorial earth it was possible to 

 satisfactorily clarif}' all grape juices and unfermented apple juices 

 made during the past season, the resulting products remaining per- 

 fectly transparent after pasteurization and retaining the character- 

 istic flavor of the untreated juices. 



The results obtained with these juices, which had previously been 

 stored for four to eight months, suggested that it might be possible 

 to clarify the juices immediately after pressing and prior to pasteuri- 

 zation. If this should tui'n out to be feasible, it would eliminate the 

 necessity for pasteurizing in a storage container, storing for some 

 months, filtering, and repacking in the final containers, thus reducing 

 the labor and cost of production and making the product immediately 

 available for use. It was further believed that the " cooked taste " 

 commonly observed in pasteurized fruit juices is due not so much to 

 loss of flavoring constituents during pasteurization as to carameliza- 

 tion and other changes produced in the suspended colloidal material 

 by heat, and it was hoped that the removal of this material prior to 

 heating might prevent the development of the " cooked taste," while 

 the elimination of one pasteurization should aid in the preservation 

 of more of the characteristic fruit flav'or than is otherwise possible. 



With these considerations in mind, work was begun with apple 

 juices as soon as material could be obtained. Xone oi the samples of 

 fruit thus far available has been of such character as to give a juice 

 of first quality, as the juices of early-maturing varieties are of 

 indifferent or poor quality, but it can be said that there is satisfac- 

 tory preservation of their characteristic flavor after subjection to 

 treatment. Samples of these juices have been pressed, treated, filtered, 

 placed in final containers, and pasteurized within two hours after 

 pressing and retain satisfactory color and flavor, comparable with 

 that of the untreated juice. Also, as anticipated, a "cooked taste" 

 does not develop in juices pasteurized subsequent to the removal of 

 the colloidal matter, and cloudiness and sedimentation do not appear 

 when such juices are repasteurized at a temperature higher than that 

 of the first treatment. 



The experiments this season have comprised some 15 varieties 

 of apples, including only the earliest maturing varieties, and the 

 material was in most cases immature. The method will be thorou<|fhly 

 tested with later maturing fruits, but the results so far obtained 

 give encouragement to believe that it will be possible to clarify any 

 and all apple juices with a very great reduction in time and labor 

 and with entire elimination of the long storage period prior to use, 

 at the same time preserving more of the characteristic flavor and 

 securing a more satisfactory appearance than has been possible 

 hitherto. 



