This section is from the book "Mrs. Rorer's Vegetable Cookery And Meat Substitutes", by Sarah Tyson Rorer. Also available from Amazon: Mrs. Rorer's Vegetable Cookery And Meat Substitutes.......
Before giving recipes for the canning of vegetables, I should like to impress upon my readers the importance of understanding surgical cleanliness. All vegetables are easily canned and kept at home, providing everything is sterile, which means dead. Foods that ferment have in them some form of either plant or animal life. The danger of spoiling is greater if sugar is used, or in vegetables containing sugar, as yeasts grow in saccharine solutions. One yeast plant in a can of corn will spoil the contents of the entire can. This is also true of peas and beets. Acid vegetables, as tomatoes, are easily kept, providing sugar is not added. Many housekeepers, ignorant of the chemical constituents of foods, add sugar to sour materials to sweeten them. It does not change the acid one particle. Sugar enters the stomach as sugar and the acid as acid. To neutralize or change the acid one must add an alkaline material. A teaspoonful of bicarbonate soda to a quart of tomatoes will sweeten them by neutralizing the acid.
To have perfect success in canning vegetables, one must follow accurately the directions given.
For convenience, have a wire rack, with a centre handle made to fit a good-sized wash-boiler.
String and wash the beans. They may be canned whole or cut. Cover with boiling water, add a teaspoonful of salt and boil rapidly twenty minutes. Drain and pack into the jars. Fill the jars with cold water, adjust the rubbers, put the tops on loosely, and proceed exactly the same as you would for asparagus, cooking it first one hour, and then thirty minutes after the lids are screwed down or fastened.
Select very young, tender beets. Put into boiling water and boil for twenty minutes; cool and slip off the skins. Pack the beets into jars. Fill the jars with cold water, adjust the rubbers, put the tops on loosely, and finish precisely the same as for asparagus, cooking the same length of time.
Select perfectly fresh green peas; shell and pack at once into clean jars. Fill the jars with cold water; adjust the rubbers, lay on the tops, and finish precisely the same as with corn, cooking the same length of time. The last boiling must be done with the jars covered with boiling water. You can succeed with both these vegetables if you follow the rules.