2 qt. red raspberries
2 qt. blueberries
7 1/2 c. sugar
2 pkg. Certo liquid pectin
1/4 c. fresh lemon juice
1 tsp. butter

You will also need 2 dozen pint canning jars.

Put clean berries in large stockpot (8 to 10-quart). Add sugar and lemon juice. Bring up to heat over medium. As the berries simmer, mash with a potato masher. We really like our jam chunky so only mash to the right consistency for you. When mixture comes to the boil and thickens and the sugar is dissolved, add the two packages of Certo and 1 teaspoon of butter to stop the foaming. Stir constantly for 1 minute.

Turn off heat and ladle into sterilized jars. Wipe the lip of the jar and place damp lids and screw rings on and hand-tighten. Turn jars upside down and leave for 10 minutes. Turn jars right side up and leave undisturbed for 24 hours. Check jars for seal and refrigerate any that did not seal properly. Can be put in pantry and left indefinitely, that is, if no one finds it.

We eat a pint jar a week. I make 3 batches of this to last a year. Never double the amounts, just make separate batches!