49. The next step consists in processing the cans of food. This may be
done either in a water bath or in a pressure cooker. If the cans are to
be processed in a water bath, keep them in the boiling water just as
long as glass jars of food would be kept there. If a pressure cooker is
to be used, keep the cans in it for 6 to 40 minutes, depending on the
steam pressure employed, the ripeness of the food or the necessity for
cooking it, and the size of the cans employed. For canning meat or fish,
processing in a pressure cooker is the most successful, as the high
temperature reached in it kills bacteria, which are difficult to destroy
at the boiling point.

As soon as the cans of food are removed from the water bath or the
pressure cooker, plunge them into cold water to stop the cooking and
prevent the food from getting soft and mushy. Then label the cans, so
that no mistake will be made as to their contents.

50. In another method, the tin cans may be closed without soldering the
caps on. The caps used in this case are different from those which must
be soldered. They are forced in place by a hand-pressure machine that
may be attached to a table. Otherwise the procedure is the same as that
just given.


OVEN METHOD

51. The OVEN METHOD oven method of canning is thought to be very
satisfactory by many housewives, but, as it is necessary to remove the
covers after cooking the contents of the jars, food canned in this way
is subjected to contamination, just as in the open-kettle method. In
addition, the jars are difficult to handle in the oven, owing to the