The “open-kettle,” or “hot-pack,” method is the oldest.  It was largely used in the pre-war days.  The food is completely cooked in the preserving kettle, and is then packed into hot, sterilized jars, after which the jars are sealed.  As the packing into the jar is done after the sterilization has been completed, there is always a possibility of bacteria and spores entering the jar with the cooked food and the air.  Fruits can be handled successfully in this way, but this method cannot be used for vegetables, greens and meats.  It is a very laborious, hot and hard way to can.  Modern housewives are discarding it more and more every year and are beginning to place their trust in the newer and far more scientific methods of canning.

The “intermittent,” or fractional sterilization, method is still beloved by some people who cling to the sure and hate to venture into the new.  Vegetables can be handled by this method as can all fruits and meats.  It is used rather extensively in the South, where they say the conditions do not favor “cold-pack.”  The great objection to this method of canning is that it requires three periods of sterilization on three different days and three liftings of jars in and out of the sterilizer.

What is sometimes called the “cold-water” method of canning should not be confused with the “cold-pack” method.  The “cold-water” is often used in connection with the canning of rhubarb, green gooseberries and a comparatively few other sour berry fruits.  If the “cold-water” method is used we would suggest that the product be thoroughly washed, placed in a strainer, scalding water poured over it, and the product then packed at once, in practically a fresh state, in the jars, and clean, cold water applied until the jars are filled.  If these steps are taken carefully and quickly the method in most cases will be successful with such acid products as I mentioned.  As the products will have to be cooked before they can be used many housewives do not consider it any saving of time or labor to follow this method.

THE COLD-PACK METHOD

The method of to-day that came into its own during the war is known as the “cold-pack” method of canning.  It fought a long fight to prove that it was a very efficient, economical and satisfactory process for busy housewives to can everything that grows.

This is the method that I shall mostly refer to in this book, and if I should omit the phrase “cold-pack” you will know that I am referring to it.  “Cold-pack” simply means that the products are packed cold in their fresh and natural state in the glass jars or containers.  To the fruits hot sirup is applied; to the vegetables hot water and a little salt are added.  The sterilization is done in the glass jars or tin containers after they are partly or entirely sealed, making it practically impossible for bacteria or spores to enter after the product has once been carefully sterilized or cooked.  In following this method vegetables should first be blanched in boiling water or live steam, then quickly plunged into cold water and the skins removed.  The products are then packed in containers and sterilized according to the instructions and recipes given later.