strawberry Jam Hasn't set properly

It's odd that here only  overripe fruit is sold/used for jam and most folk have no problem with set - mind you maybe they boil it for a week! a friend made my apricot jam for me last year ( I fell out of the tree whilst picking the fruit, broke my spine and was laid up for 3 months ) and it came back to me an interesting shade of brown - yummy, but brown!  This year I picked my apricots from another tree (no climbing required) just before going for more surgery on my spine and another 3 month layoff (or should I say, laydown) and froze them, so I'll make my own (non-brown) jam this year when I am better.