UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 702 



Contribution from the Bureau of Chemistry 

 CARL L. ALSBERG, Chief 



S\J9-"^^L. 



Washington, D. C. 



V 



September 12, 1918 



EFFICIENCY OF COMMERCIAL EGG CANDLING. 



By M. K. Jenkins, Assistant Bacteriologist, assisted by C. A. Bengtson, 

 Investigator in Egg Handling. Prepared under the direction of M. E. 

 Pennington, Chief, Food Research Laboratory. 



CONTENTS. 



Page. 



Purpose of investigation 1 



Plan and scope of investigation'. 2 



Relation of quality of eggs to accuracy in 



candling 3 



Efficiency of candling bad eggs in receipts ... 6 



Bad eggs distinguishable by candling 6 



Bad eggs not distinguishable by candling 10 



Efficiency of candling rejects 11 



Good eggs in rejects 11 



Accuracy in recandling rej ects , 13 



Accuracy of candling crews 14 



Experienced candlers vs. inexperienced 



candlers under good management 14 



Inexperienced crews under poor man- 

 agement 17 



Essentials of good management 18 



Summary 18 



PURPOSE OF INVESTIGATION. 



It is common knowledge among those buying and selling eggs 

 that grading by the candle is not an absolutely dependable method 

 for the separation of good and bad eggs. As it is the best method 

 known for determining the quality of eggs in the shell, however, it 

 is important to learn its degree of efficiency. This bulletin aims to 

 show the effectiveness of commercial candling in detecting different 

 dnds of good and bad eggs, as well as the variations in efficiency of 

 different candling forces. In a previous publication,^ prepared as 

 a guide to beginners wishing to learn how to candle eggs, detailed 

 descriptions, accompanied in many instances by illustrations, are 

 given of the different types of good and bad eggs of common occur- 

 rence. The classifications and descriptive terms given there are used 

 in this publication. 



The purpose of the investigation here reported, then, may be sum- 

 marized as follows: To find (1) the relative error in the candling of 

 different types of good and bad eggs; (2) the relation of the quality 



58079° — 18 — Bull. 702- 



1 U. S. Dept. Agr. Bui. 565. 

 1 



