Just came back home from holiday,and saw a lot of blackberries in the garden,ready to pick...It was more then 1Kg !!
If you want to make jam you need 500 gr blackberries the juice of 1 lemon and 250 gr jellysugar.
Wash the blackberries and put them in a pan with the jellysugar and the lemon. Let it cook for about 15 min. and put the hot jelly in clean pots and close them,turn up side down for 5 min. and let it rest for a few hours. Enjoy !!