BLEACHING OF OATS WITH SULPHUR DIOXID. 



grain can be shipped Ivitk'safety. Some operators prefer to add 

 as little moisture as possible, in which case the product merely 

 requires cooling before shipment. Others maintain that they get 

 a better-appearing product by adding considerable moisture, and 

 then drying out the excess before shipment. 



The bleaching of oats and barley as practiced at the present time 

 is a continuous process after the apparatus has once been set in 

 motion, and very little attention is required except to see that the 

 proper supply of sulphur is kept in the furnace, the proper amount 

 of water is added, and that the grain is kept at a uniform flow. 

 Some of the largest and most efficient bleaching plants have capac- 

 ities of 2,000 bushels of grain per hour. 

 Photographs of sulphur-bleaching apparatus 

 are shown in figures 1, 2, and 3, which illus- 

 trate some of the leading types of commercial 

 bleachers. 



CHARACTER OF INVESTIGATIONS. 



In the fall of 1915, samples of oats were 

 collected from representative sections in 

 which the commercial bleaching of oats is 

 practiced to a considerable extent, and these 

 samples were carefully examined and ana- 

 lyzed. The analyses of samples from the 

 same lots of grain before and after bleaching 

 were compared. Using these data as a basis 

 loT further investigations, additional experi- 

 ments were undertaken. Visits were made 

 to some of the most important elevators 

 throughout the Middle West that operate 

 bleachers. Samples of as many different 

 grades and qualities of oats as possible were 

 obtained and studied. These were bleached 

 by the regular process in vogue at the ele- 

 vator, and also by modifications of this method which suggested 

 themselves to the writer or were suggested by the operator of the 

 elevator. Careful attention was paid to the amount of water 

 absorbed, the atmospheric conditions, and the condition and 

 appearance of the oats before and after bleaching. An endeavor 

 was made at aU. times to improve if possible the appearance of the 

 final product. 



Each different grade or quality was carefully studied before and 

 after treatment, and as many types of damaged oats as possible 

 were obtained and examined. The effect of bleaching on each kind 



Fig. 1. — A modern grain bleacher. 



