Prepare mason jars and lids by washing and sterilizing in boiling water or running through the sterilization cycle on the dishwasher.
Prepare the strawberries and raspberries. Rinse with cool water. Slice strawberries into halves or quarters and then crush them with a potato masher. Crockpot jam cooks best the smaller the pieces are broken down beforehand.
Add sugar, pectin, strawberries and raspberries to the crockpot.
Set the crockpot on high and cook for 2-3 hours, stirring every 30 minutes.
When the sugar is completely dissolved throughout the entire mixture, the jam is done. Ladle jam into prepared jars, secure lids, and leave the jars to set for 24 hours before storing in the freezer.
If, instead of storing in the freezer, you’d like to process the jars in a boiling water bath, they can be stored on the shelf for up to 1 year.