Question: My strawberry jam just won't set, regardless of how long I boil it. What's wrong?
Strawberries are one of the fruits that is low in acid and pectin – both of which are required to make jam set; lemon juice can be added and the jam re-boiled until it jells when tasted.
However, if the jam has darkened in colour and has a caramel taste (which happens when the sugar is overcooked) it cannot be re-boiled.
If the flavour of the jam is still okay, commercial pectin (available in powdered form from health-food stores and supermarkets) can be added to help set the jam; just follow the directions on the packet.