I've had really good success making strawberry jam (in fact I made over 100 jars as my wedding favours).
I'm wanting to make some blackberry jam & blueberry jam (2 seperate jams, i'm not planning to mix the berries). Can I use my original strawberry jam recipie, but just substitute strawberrys for the blackberries & blueberries?
The recipie is as follows:
3 pounds (9 cups) strawberries
4 cups sugar
1/3 cup lemon juice
1 tablespoon butter
How confident are you in your preserve-making abilities? I've only been making my own jam and jelly for four years and haven't had any problems until last weekend when I made my first blueberry jam. So I'd look up a recipe to be on the safe side and also, don't expect the cooking experience/signs to be the same as other fruit, which is the mistake I made with the blueberry jam.
I used the Chow recipe (http://www.chow.com/recipes/11050-fra...) and even though I followed the recipe to the letter, my jam got overcooked so it's quite stiff. If you do make blueberry jam, here's where I think I went wrong: based on my other preserve-making experience, I was waiting for it to thicken a bit but I'm pretty sure that if I had pulled it off the heat once the bubbles subsided, it'd be fine and I'd be eating it on waffles in the morning instead of trying to figure out what to do with three and a half cups of hard jam. Sigh...
Blackberry jam is also on my list of jams to try. Last summer I made my first strawberry jam using Nigella Lawson's recipe with balsamic vinegar and it turned out absolutely beautiful - I'm hoarding the last jar of it right now! :)
Good luck with your jams!