I made a slap-dash effort at sterilization. Please don't send the food safety police after me. I did wash everything in hot soapy water and then put the glass in the oven at 250 while the jam cooked.
*Cue Space Odyssey theme music* Behold: I have made jam! Okay, I've made it before, whatever. But this is really good jam. It has a good balance of fresh berry and lemon flavor, and big whole berries still in it. I love seeing a chunk of the real stuff in what I'm eating. No baby food, thankyouverymuch, I have teeth and I will use them, even on jam.
Other than the sterilization stuff, the jam making process was pretty easy. Toss it all in a large dutch oven, cook on medium high heat so that it bubbles, stir so it doesn't burn, and cook until thick. I initially used 10 cups of blackberries, 4 cups of sugar, 2 lemons and their zest. For me, it was way cloyingly sweet, so I added one more lemon, juice and zest and 1 cup raspberries, and cooked it a little longer. It was probably 45 minutes in all. I smashed some of the berries with a spoon, but not too much. Carefully! spoon into jars, seal and cool. Good to go.
The flavor was nice, fruity and with fresh flavor from the lemons, but no sourness at all. It was still a little too sweet, though. I'm going to start with less sugar next time and taste and see.