Originally Posted by
charley26
Slightly under ripe fruit is better of jam, I think blackberries (here anyway) are not high in natural pectin, so I use 'jam sugar' when making it, and a little lemon juice, no water. I add the sugar to the blackberries and leave to 'mix' overnight, and make the jam the following day. There will be plenty of juice/liquid in the pan. Heat slowly until the sugar dissolves, the bring to a boil until setting point is reached.
I haven't make blackberry jam but have made strawberry, raspberry, black currant, grape, mixed fruit, and apricot jams - all without purchased pectin. I only add lemon juice and sugar to the fruit. It's a little more unpredictable in cooking time than when using purchased pectin but I greatly prefer the taste. I did do the overnight method with apricots and it was delicious. I will try the overnight with other fruits this year and see how it goes.
The blackberries in whiskey sounds interesting - not sure which I would like more the flavored whiskey or the soaked fruit!