VACUUM-PRESSURE IN GLASS CANNING JARS 



17 



The data obtained from these cooperators were tabulated and are presented 

 in Tables 3 and 4. Several hundred of these jars were examined by the authors. 



Table 3. — Results of Reports from Home Canners using the Fully 

 Sealed Method of Canning. 



Number of cooperators 64 



Number of reports received 56 or 



Number of jars Issued Reported 



87 percent 



Pints 2,772 



Quarts 2,640 



Half gallons 174 



Totals 5,586 



2,338 



2,148 



174 



4,660 or 84 percent 



Additional jars reported 



Quarts 2,404 



Half gallons 9,524 



Total 11,928 



Total jars reported 16,588 



Breakage Jars 135 or 0.81 percent. 



Covers 55 or 0.33 percent 



Total 190 or 1 . 14 percent 



Method of processing Number of jars Breakage 



Steam pressure — 10 pounds, 240° F 2,287 21 or 0.91 percent 



Water bath — 212° F 14,287 169 or 1 . 18 percent 



Electric oven — 275° F. 14 



Totals 16,588 



Loss of liquid None 



Pints 1,901 



Quarts 2,696 



Half gallons 9,597 



Totals 14,194 



Percent 85.5 



Slight 



494 



1,176 



61 



1,731 

 10.4 



There was no serious breakage nor loss of liquid in any one case. The most 

 dangerous breakage reported was that of a jar which "cracked with some 

 violence." Usually cracked jars can be lifted out of the retort or water bath 

 in one piece. One cooperator inadvertently permitted the pressure in the 

 cooker to rise to 30 pounds. Upon opening the cooker she found that there 



