2 packages (1-3/4 ounces each) powdered fruit pectin
7 cups sugar
In a large saucepan, combine berries and lemon juice; crush slightly. Stir in pectin. Bring to a full rolling boil over high heat, stirring constantly. Stir in sugar; return to a full rolling boil. Boil and stir 1 minute.
Remove from the heat; skim off foam. Ladle hot mixture into nine hot pint jars and one hot half-pint jar, leaving 1/4-in. headspace. Remove air bubbles and adjust headspace, if necessary, by adding hot mixture. Wipe rims. Center lids on jars; screw on bands until fingertip tight.
Place jars into canner with simmering water, ensuring that they are completely covered with water. Bring to a boil; process for 10 minutes. Remove jars and cool.