1lb. mixed berries -
cherries (bitter are very good), blueberries, and redcurrants* (depipped, destalked etc.)
1 apple - peeled, cored and cut into smallish pieces
1 lemon - juice only
Simmer all the ingredients for approx. 20 mins. until the fruit is soft and shiny. Stirring.
* if you dont use redcurrants, you wont need to sieve the jam - supplement with other fruit instead.
For 8ozs. of sieved puree add 6ozs. of sugar - (jam sugar or other).
Boil gently - stirring so it doesn't stick - until 'jammy'.
I think you get a firmer set with Jam Sugar as it has added pectin.
Test for readiness, by putting blobs onto a cold saucer - if it wrinkles and sets - it's done.
Dont overcook the jam - it's better slightly softer than too thick.
Cool slightly, pour into sterilised jars* and seal.
I find a jam funnel is very useful as the jam tends to go straight into the jars, rather than everywhere else!
*I sterilise my jars in the oven at 190 deg. C, for approx. 20 mins., and sterilise the lids by pouring boiling water over them - though you can put them in the oven too. Do take care when removing the hot jars, and cool them down before filling them with the jam.