Aunt Duddie Makes Seedless Blackberry Jam

UPDATE... A few people through the years have asked me why I don't use my berry strainer for the KitchenAid stand mixer. My answer is simple - KitchenAid does not recommend running blackberries through the strainer because the seeds are so hard they will potentially break the strainer. I like using the Mouli and it's just as fast as the berry strainer with less clean-up.
Excuse my sore throat but this is my favorite jam!
I use the recipe that comes with the Sure Jell premium fruit pectin insert which is what Grandma Addie told me to use. The only change I make is to run the berries through a fine mouli strainer food mill to get rid of the hideous seeds. I love to mix a teaspoon of blackberry jam into home-made yogurt. It's so easy to make! If you like blackberries you'll love this jam!