18 



MASS. EXPERIMENT STATION BULLETIN 341 



was neither breakage nor loss of liquid in the jars of that batch. It is interesting 

 to note that the percentage of breakage in water-bath processing and in 

 pressure-cooker processing is about the same, viz., 1 percent. 



Although cautioned not to fully seal glass jars in oven canning, one co- 

 operator did process 14 quarts of tomatoes for 90 minutes at 275° F. in an 

 electric oven. Although no difficulties were encountered in this instance, it is 

 still deemed inadvisable to use oven canning, particularly for fully sealed jars. 



Meat products and corn caused the most difficulty in canning, both in the 

 laboratory and afield. It was in the canning of these products that reports 

 showed that several jar rubbers were pushed out beyond the point of effective 

 sealing. This was true mainly in the case of meat where the fat tends to grease 

 the rubber ring and permits the internal pressure to push it out easily, causing 

 a "blown" condition and a faulty seal. Partial sealing does not prevent this 

 undesirable condition. A very large headspace, approximately one or two 

 inches, lessens the extent of lubrication by the fat and largely prevents the 

 blowing of rubber rings. In several instances jars of corn showed marked loss 

 of liquid. However, in the laboratory canning of corn care was taken to keep 

 the sealing rim of the jar free of corn particles and good results were obtained. 



Of the 16,588 jars processed fully sealed, cooperators reported no noticeable 

 loss of liquid in 85.5 percent, slight loss in 10.4 percent, moderate loss in 2.2 

 percent, and marked loss in only 0.6 percent. 



The results of this practical field test, combined with innumerable favorable 

 reports received from canners for the 1936 canning season, substantiate the 

 results of the laboratory tests and show that the fully sealed method of pro- 

 cessing, as recommended, is a distinct improvement over the partially sealed 

 method of processing as formerly advocated. 



Table 4. — Products Packed by Cooperators 



Fruits: 



Applesauce 



Blackberries 



Blueberries 



Cherries 



Currants 



Fruit juices 



Fruit syrups 



Grape ade 



Grape juice 



Grape sauce 



Peaches 



Pears 



Plums 



Raspberries 



Raspberry jam 



Miscellaneous: 

 Mushrooms 

 Pectin 



Vegetables: 



Beans — lima 



shelled 

 string 



Beets 



Broccoli 



Carrots 



Cauliflower 



Corn 



Peppers 



Pimentos 



Squash 



Tomatoes 



Tomato juice 



Tomato paste 



Tomato puree 



Vegetable soup 



Meat and Fish: 



Beef broth 



Fish 



Fish flakes 



Ham 



Hamburg 



Lamb chops 



Meat 



Pork, roast 



Sausage 



Veal 

 Pickles: 



Beets, pickled 



Chili sauce 



Mustard pickle 



Pepper relish 



Piccalilli 



Sweet mixed pickle 



