Boysenberry Jelly

Instructions

• Inspect four 32-ounce jars for cracks and rings for rust, discarding any defective ones. Immerse in simmering water until jelly is ready. Wash new, unused lids and rings in warm soapy water.
• Crush boysenberries in a large bowl with the back of a spoon or a potato masher. Add crushed fruit into a sieve or cheesecloth set over a bowl and let juices drip into the bowl until dripping stops. Press gently to get as much juice out of the berries as possible. Measure 4 cups of juice into a large pot. If necessary, add up to 1/2 cup of water to get the exact amount of juice.
• Stir sugar into the juice and butter to reduce foaming.
• Bring mixture to a full rolling boil over high heat, stirring constantly. Stir in pectin quickly. Return to a full boil and boil exactly 1 minute, stirring constantly. Remove from heat.
• Skim off any foam with metal spoon. Ladle quickly into prepared jars, filling within 1/8 inch of tops.
• Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil and lower jars 2 inches apart into the boiling water using a holder. Pour in more boiling water to cover jars by at least 1 inch. Bring to a rolling boil, cover, and process for 5 minutes.
• Remove jars from water and cool. Let stand at room temperature for 24 hours.