Put a plate in the freezer
Wash, hull and cut up strawberries. Cover in 1 cup sugar and Balsomic Vinegar
Cover and set aside for 30 minutes, mix after 15 minutes
In a large stockpot full of water, place 7 half-pint (8 oz) jars in the pot and turn the temperature to medium.
In a large bowl, mix together remaining sugar and pectin. Whisk to combine.
Place Strawberries into a heavy bottom stock pot and turn to medium heat. Add the sugar pectin mixture and continue to cook. Bring Jam mixture to 240 degrees allow to bubble for a few minutes.
Use a potato masher or emersion blender to mash strawberries. A potato masher will result in a lumpier jam, while an emersion blender will make a smoother jam.
To test the jam on a chilled plate, pour a drop of the boiling jam on the plate, put it in the freezer for a minute or two. When you take it out, swipe your finger through the center of the jam. If it is still runny, your jam needs a few more minutes of cooking. If your jam has set, it will crinkle against your finger.
When the jam is ready, remove the jam from the heat. Retrieve jars from the hot water and place them on a towel next to your stove. Ladle the jam into prepared jars.
Process the filled and closed jars in the water bath for 15 minutes. Remove from the water and set aside to cool off. Do not move until jars are room tempature. Any jars that did not seal should be put in the fridge for immediate use.