Sterilize 5-6 8-ounce jars, keep hot. Heat lids and rings in hot water, keep warm but not boiling. Fill water bath canner and bring to boil.

Place elderberry juice and lemon juice into stock pot. Stir in pectin. Add butter to reduce foaming. Bring mixture to full rolling boil (boil that doesn’t stop bubbling when stirred) on high heat, stirring constantly.

Stir in sugar. Return to full rolling boil and boil 1 min., stirring constantly. Remove from heat.

Ladle into prepared jars, filling to within 1/8 inch of tops. Wipe jar rims and threads. Cover with two-piece lids. Screw bands tightly.

Place jars on elevated rack in canner. Lower rack into canner. (Water must cover jars by 1 to 2 inches. Add boiling water, if necessary.)

Cover; bring water to gentle boil. Process 10 minutes.

Remove jars and place upright on towel to cool completely. After jars cool, check seals by pressing middles of lids with finger.  (If lids spring back, lids are not sealed and refrigeration is necessary.) Makes 5-6 eight ounce jars of jelly.