Jam: how to set
Jam that won’t set is very frustrating. The juice of a lemon can sometimes help. Special pectin sugars are now available which mean you don’t need to use pectin from a sachet. The main thing to remember is that it’s okay to keep boiling the fruit beyond the time your recipe suggests; this is often all it takes to get the jam to a consistency that’s just perfect. Another trick is adding some finely chopped greenish rhubarb, which is a natural source of more pectin.