New YorK AGRICULTURAL EXPERIMENT STATION. 53 
SWELLING OF CANNED PEAS. 
Causge DETERMINED. 
INTRODUCTORY NOTES... 
In peas, acid is lacking, the amount of sugar and nitrogen is 
such as to favor fermentation, and heat alone must be relied upon 
to prevent decomposition. Add to this the fact that heat pene- 
trates the cans rather slowly and it is seen why peas are among 
the most difficult vegetables to can satisfactorily. 
In 1902 our attention was called to a serious outbreak of swell- 
ing in the product of a large factory. In connection with this 
work we attempted to determine three point's: (1) The cause of 
the trouble, (2) the amount of heating necessary to obviate the 
trouble, (3) the limit of heating which was practical without 
injury to the commercial quality of the peas. 
In order to test these results under commercial conditions and 
in order to determine the limit of heating which peas would stand 
without injury it was necessary to work with fresh peas at a 
factory. The Geneva Preserving Co. very kindly gave us every 
facility for carrying out this work at their plant and in this con- 
nection we canned a ton of peas, including early and late varie- 
ties, under actual factory conditions. 
The lively and helpful interest which all members of the force 
took in the work was one of its most pleasant features and to them 
we return our sincere thanks. We are especially indebted to 
Manager Thorne, upon whose experience we have drawn largely 
throughout the progress of the work. We are also indebted to 
the canners of the State who by furnishing information on vari- 
ous points have enabled us to give an additional test to the prac- 
ticability of our conclusions. 
PREVIOUS STUDY OF THIS PROBLEM. 
The swelling of canned peas was, so far as we have been able 
to learn, the first trouble of this nature to be successfully attacked 
by modern science. In 1895 Russell? studied an outbreak in a 
Wisconsin factory. He found that the swelling was the result 
of the action of germs which had survived the heating process and 
*Gaseous Fermentations in the Canning Industry. Wis. Agr. Exp. Station 
12th Ann. Rept., 1895; p. 227. 
