weepiper
I fix the machines that fight climate change
Yeah those ones
well then YOU NEED TO ADD PECTIN OR IT WON'T SET. That's why I said to use jam sugar, it has pectin in it, makes it much easier. You can fanny about with lemon juice and apples if you like but it won't be as jammy.

You might need quite a few, brambles are notorious for being difficult to get to set when you make jam or jelly with them.