6 cups fresh blackberries
3 cups sugar
1 1 3/4 oz. package of dry pectin
- Add the blackberries to a large pot or Dutch oven.
- Using a potato masher, crush the blackberries. Do not use a food processor to do this step.
- Add the pectin powder to the blackberries and stir.
- Heat the blackberries over medium-high heat until they begin to boil.
- Add the sugar to the mixture and stir.
- When the blackberries begin to boil again, remove them from the heat and ladle the mixture into clean, hot mason jars. Leave 1/4 inch space at the top.
- Wipe the rim clean using a cloth. Then place canning lids and rings on top of each jar so that they are on tight.
- Place the jars in a canner that is filled with hot water to a depth of 1 inch above the tops of the lids of the jars.
- Bring the water in the canner to a boil for 10 minutes, then remove the jars from the canner using tongs.
- Let the jam cool for 12 hours. During this time, the jam inside will contract forming an air-tight seal.