Layer berries with sugar and leave them in the fridge for 3-4 hours or overnight.
Bring to a boil over the medium-high heat, stirring often. Boil for 3-4 minutes.
Ladle into the sterilized jars and seal. Enjoy!
*Though the total time for preparation and cooking is showing as 25 minutes, there is still a "passive" period of 3 to 4 hours (or overnight) of berries layered with sugar being in the fridge to release juice.