Put it back into pan, boil with pips for pectin, simmer/stew & keep stirring so's it doesn't burn & stick to pan.....for 1hour at least. To test: drip onto plate to see if skin forms when cooled.
I didn't realise I could put it back in the pan to boil again.
I am mostly making Blackcurrant jam but some with Apple and Blackcurrant.
When it sets it is realy nice but only 1 lot set so far. I think I shall try to put the two lots that didn't set back in the pan with some more pectin.
You don't need to boil for a whole hour! (Not sure about bkc and apple) but bkc alone takes approx 15 mins, and for that you don't need pectin. I don't have a thermometer and don't really see the need for one. Just keep a steady rolling boil and it should be fine. I've made 3 lots this way.
Not much use now, but have you tried using Jam Sugar ? All the supermarkets have it. It contains pectin and is jolly good for getting a good set with almost all fruits.(I still have trouble with strawberry, though.)