Blackberry Jelly

Ingredients

Instructions

1. 1Wash 5 half-pint jars in hot soapy water, rinse well, then place them in a boiling-water canner, cover with water, and boil for 10 minutes to sterilize, since the total processing time for this jelly is less than 10 minutes; keep the jars hot in the water until you are ready to fill them.
2. 2Simmer the new lids in a small pan of hot (not boiling) water per the manufacturer's instructions and keep them warm.
3. 3Wash the screw bands in warm soapy water and set aside.
4. 4Rinse 4 pounds of blackberries, place them in a large pot with 1/2 cup water, crush slightly, and simmer, covered, for about 10 minutes, stirring occasionally, until the berries are very soft.
5. 5Extract the juice by pouring the cooked berries into a dampened jelly bag or several layers of cheesecloth suspended over a bowl, and let it drip, undisturbed, for at least 2 hours (do not squeeze the bag, or the jelly may turn cloudy); measure out exactly 4 cups of juice.
6. 6Combine the 4 cups of blackberry juice with 1/4 cup bottled lemon juice and the full box of powdered pectin in a large saucepot.
7. 7Bring the mixture to a full rolling boil over high heat, stirring constantly, then add all 5 1/2 cups of sugar at once.
8. 8Return to a full rolling boil that cannot be stirred down and boil hard for exactly 1 minute, stirring constantly.
9. 9Remove from the heat and skim off any foam.
10. 10Ladle the hot jelly into the hot, sterilized half-pint jars, leaving 1/4 inch of headspace.
11. 11Slide a non-metallic spatula around the inside of each jar to release air bubbles, wipe the rims clean, center a warm lid on each jar, and screw on a band until fingertip tight.
12. 12Process in a boiling-water canner with jars covered by 1 to 2 inches of water for 5 minutes for half-pint jars (also 5 minutes for pint jars), starting the timer once the water returns to a full rolling boil.
13. 13Adjust for altitude: add 5 minutes at 1,001-3,000 feet, 10 minutes at 3,001-6,000 feet, 15 minutes at 6,001-8,000 feet, and 20 minutes above 8,000 feet.
14. 14Turn off the heat, wait 5 minutes, then remove jars to a towel-lined counter and let cool undisturbed for 12 to 24 hours away from drafts.
15. 15Check each seal once cool (the lid should be concave and should not flex), remove the bands, wipe the jars, and label with contents and date.
16. 16Store in a cool, dark place for up to 1 year for best quality; refrigerate after opening and use within about 3 weeks.
17. 17Do not change the ratio of juice, sugar, lemon juice, or pectin, since this exact balance is what makes the jelly both safe and properly set.