Here is my recipe for Cherry Berry Jam
12 c cherries
4 c raspberries
4 c blackberries
4 Granny Smith apples
1/2 c lemon juice
1 c homemade pectin
10 c sugar
I use frozen fruit because these three do not ripen at the same time. I bring out the needed fruit a day or two ahead and thaw it in the fridge before making the jam. I use pitted cherries and squish them as I put them into the pot. It serves two purposes - to check for missed pits and to make it easier for the cherries to break up during the jam process. The first time I made cherry jam I didn't do this and had to try to squash the cherries with a potato masher part way through cooking. It is easier to squish them before cooking than mash them while they are steaming hot.
The blackberries are a thornless variety that grow in our yard. I don't know if we have two varieties but some of the berries grow much larger than the rest. The small ones are also harder to pick as they don't release from the stem as easily as the larger ones.
The raspberries here seem to have a better crop in late summer. They do produce in the spring but the berries are small and dry out quickly. In the latter part of August and on into September and even October - we have big, juicy berries.
I peel, core and chopped the apples. The apples not only add natural pectin but give little appley bits to add texture to the jam. Some apples mush-up quite readily when you cook them, but grannies seem to hold their shape better.
Mix all ingredients except the sugar in a large pot and cook until fruit in soft and breaking apart. Add sugar and continue boiling and stirring until it reaches the jam stage. (either 220°F on a candy thermometer or the cold saucer test)
Pour into sterilized jars and process for 10 minutes in hot water bath. The recipe makes 10 - 11 pints. Enjoy! ;)