AT WHAT TEMPERATURE SHOULD PEAS 

 BE PROCESSED?* 



H. A. HARDING and J. F. NICHOLSON. 



Our attention has been called to the losses which occur due to the 

 swelling of canned peas. The cause of this trouble has been found 

 and a temperature at which the trouble can be controlled has been 

 determined. Before making final recommendations it is desired to 

 test a number of temperatures upon cans of fresh peas to find the 

 effect upon their commercial value. This circular is a report of work 

 done and is intended for those engaged in the canning industry with 

 the hope that it may be of some use to them during the present season. 

 We wish to acknowledge our indebtedness to the canners for their 

 suggestions and cooperation and especially request information upon 

 the efifect of various temperatures upon the commercial quality. 



Cause of the swelling. — The swelling is due to gas produced by 

 bacteria growing within the cans. It is quite possible that different 

 species of bacteria might cause this swelling but thus far we have 

 found but a single form that seems to be responsible for this trouble 

 on a commercial scale. The spore-forming bacillus is hard to kill 

 because it forms unusually resistant spores. These spores are so 

 resistant that any treatment which will destroy them will probably 

 suffice for any other forms which may be present. 



Source of the bacilli. — The source of the gas-forming baccilli, 

 whether from the factory or the pea vines, has not been determined. 

 They do not seem to be always present in either, since during some 



*A reprint of Circular No. 3, new series. 



