In no department of preserving does the housekeeper feel less sure of
the result than in jelly making. The rule that works perfectly one time
fails another time. Why this is so the average housekeeper does not
know; so there is nearly always an element of uncertainty as to the
result of the work. These two questions are being constantly asked: "Why
does not my jelly harden?" "What causes my jelly to candy?"
It is an easy matter to say that there is something in the condition of
the fruit, or that the fruit juice and sugar were cooked too short or
too long a time. These explanations are often true; but they do not help
the inquirer, since at other times just that proportion of sugar and
time of cooking have given perfect jelly. In the following pages an
attempt is made to give a clear explanation of the principles underlying
the process of jelly making. It is believed that the women who study
this carefully will find the key to unvarying success in this branch of
preserving.