Select blueberries. Fresh is best, hand picked even better.
Wash jars and lids. The dishwasher is great for this or wash jars in hot, soapy water. Rinse well. Keep jars in hot water until ready to use or keep jars in the dishwasher on "heated dry" cycle.
Wash and sort blueberries. Remove any bits of stems, leaves and soft or mushy berries.
Blanch blueberries. Place berries, (up to 8 cups at a time) in a large pot with at least 1 gallon of boiling water. Boil each batch for 1 minute after water returns to a boil. Drain and keep hot fruit in a covered bowl.
Mix 1/4 cup plus 1 tablespoon clear jel with 3/4 cup sugar in a large pot. Stir in 1 cup blueberry juice or water. Heat until mixture thickens and begins to bubble. Add 3 1/2 teaspoons lemon juice, stirring constantly.
Fold the warm blueberries into hot liquid. Stir gently
Fill jars with blueberry mixture. Remove air bubbles. Fill jars to within 1 inch from tops. Wipe any spilled filling off the rims. Seat lid and tighten the ring.
Process filled jars in hot water bath. Put the filled jars in the canner. Keep the jars covered with at least 1 inch of boiling water. Process for 30 to 35 minutes.
Remove and cool jars. Lift jars out of water. Let cool without touching or bumping each other for 24 hours. Make sure jars are sealed. Listen for the ping sound while jars are cooling.