THE CLARIFICATION OF FRUIT JUICES. 27 



after pressing, in order to permit the settling of cellular debris, and 

 should then be siphoned or decanted from the sediment. 



(10) The best results are obtained when the juices are thoroughly 

 mixed with the diatomaceous earth at the rate of 6 to 8 pounds per 

 100 gallons and immediately filtered through a properly supported 

 layer of the earth. 



(11) During the filtration the juice on the filter should be thor- 

 oughly agitated occasionally, to keep the earth in suspension and 

 prevent the sliming and choking of the filter. 



(12) A number of filtering devices have been found satisfactory 

 for use in filtering treated juices. The construction and operation 

 of simple but effective filters adapted to use in home or semicommer- 

 cial operations are described. Filters employing pulp are not suited 

 to the purpose. 



(13) Heating the liquid prior to mixing with the earth and filter- 

 ing considerably increases the rate of filtration. If heating is con- 

 ducted in open vessels or tanks, the temperature of the juice should 

 not be allowed to exceed 130° to 140° F. and should not be long main- 

 tained at this temperature in the case of apple juices and the more 

 delicately flavored grape juices or deterioration in flavor will occur. 

 A few varieties of grapes yield juices which may be heated to 170° 

 F. in open vessels without loss of flavor. 



(14) Juices filtered with the aid of properly prepared diatomace- 

 ous earth on a suitable filter after previous sedimentation for 12 to 18 

 hours remain perfectly clear and transparent when bottled and pas- 

 teurized and retain the characteristic flavor and quality of the fresh 

 juices in high degree. 



(15) The employment of the methods of treatment herein de- 

 scribed materially reduces the labor of preparing apple, grape, and 

 grapefruit juices by eliminating preliminary pasteurization and stor- 

 age in order to permit sedimentation, thus shortening the process of 

 preparation and making it a continuous process. Losses from spoil- 

 age and breakage during this storage period are eliminated by mak- 

 ing packing in the final containers possible ; and a material improve- 

 ment in the appearance of the product, together with a better preser- 

 vation of flavor, is obtained. 



