For the vineyard peach blueberry jam, first pit the vineyard peaches and grind them together with the blueberries in a saucepan, using a hand blender, until a puree is formed.
Add the preserving sugar and lemon juice to the fruit puree and set aside. Wash out the jam jars and lids while hot, place the jam in a pan of cold water so that the jars do not crack when filled.
Bring the fruit jam to a boil, stirring constantly. If foam forms, skim it off. Then simmer the puree for 4 minutes while stirring.
Then, using a funnel, pour the vineyard peach blueberry jam into the jam jars until they are completely full and close them tightly. Turn the filled jam jars upside down until they are completely cool.