How to Make It
Combine the first 2 ingredients in a 4-quart stainless steel or enameled Dutch oven. Crush berries with a potato masher.
Stir in pectin. Bring mixture to a full rolling boil that cannot be stirred down, over high heat, stirring constantly.
Stir in agave syrup. Return mixture to full rolling boil. Boil hard 1 minute, stirring constantly. Remove from heat. Skim foam, if necessary.
Ladle jam into a hot jar, leaving 1/4 inch headspace. Remove air bubbles. Wipe jar rim. Center lid on jar. Apply band, and adjust to fingertip tight. Place jar in boiling-water canner. Repeat until all jars are filled.
Process jars 10 minutes, adjusting for altitude. Turn off heat, remove pot lid, and let jars stand 5 minutes. Remove jars and cool.