This section is from the book "Hints To Housewives On How To Buy, How To Care For Food", by Mayor Mitchel's Food Supply Committee. Also available from Amazon: Hints to Housewives on How to Buy, How to Care for Food.
One secret of success in canning is cleanliness. For this reason, keep the room as free as possible from dust; keep the table, your hands, and your clothes clean while you work; and wash all the utensils just before beginning work; rinse them with boiling water, and let them dry without wiping.
To Sterilize Jars: Put the jars in a pan or pail, cover with cold water, let it come to a boil and boil for ten minutes. This is an extra precaution, not necessary except when fruit is cooked before being put into jars. When it is done, covers and rings should be sterilized in a smaller vessel in the same way.
To Test A Jar: Fill a jar with water, fasten on ring and cover, and invert. If it leaks, either the jar is imperfect or the rubber poor. Use no jar that cannot be made absolutely tight.
When Breakage Of Jars Occurs It Is Due To Such Causes As:
2. Placing the cold jars in hot water or vice versa. As soon as the jars are filled with hot syrup or hot water, place them immediately in the boiler.
3. Having the wire fastener of glass-top jars too tight, thus breaking the jars when the lever is forced down.
4. Allowing a cold draft to strike the jars when they are removed from the boiler.
The Right Sort Of Fruit To Can: Can each fruit in its season when it is best and cheapest. It is best for canning just before it is quite ripe. The better the condition of the fruit the easier it is to sterilize. So use only fresh, clean, sound fruit, and see that no soft berries or spoiled bits get into the cans.
To Cook Fruit In Jars In A Closed Vessel The Following Outfit Is Necessary: A wash boiler, pail, or any vessel with a tight-fitting cover, large enough to hold several jars; a rack to fit the bottom of the boiler and keep the jars from bumping and breaking when the water boils (this may be a piece of heavy wire netting or it may be made at home of strips of wood); quart or pint glass jars (the jars with glass covers and metal springs are best); a new rubber ring for each jar (old rubber may not be air-tight); large bowl or enamelled pan for fruit; plated knife and fork; plated or enamelled spoon; quart measure; half-pint measure; scales; saucepan for syrup. Avoid iron and tinware in canning.