Old-Fashioned Blackberry Jelly

Directions

1. 1
   Put the blackberries in a wide, 6- to a-quart preserving pan and crush them with your hands.
2. 2
   Add 1/2 cup water and bring to a boil; boil until the berries are tender and have released their juices, about 5 minutes.
3. 3
   Set a large, very-fine-mesh sieve (or jelly bag) over a deep bowl or pot.
4. 4
   Pour the blackberries into the sieve and let drain for 30 minutes, stirring occasionally but not pressing down too hard on the solids; discard the solids.
5. 5
   Measure the juice; you should have about 4 cups.
6. 6
   Prepare for water-bath canning: Sterilize the jars and keep them hot in the canning pot, put a small plate in the freezer, and put the flat lids in a heatproof bowl (see Notes for details).
7. 7
   Rinse the preserving pan and pour in the blackberry juice.
8. 8
   Add 3/4 cup sugar for each cup of juice, then add the lemon juice.
9. 9
   Bring to a boil over high heat and cook, stirring occasionally, until the mixture registers about 220F on a candy thermometer or a small dab of it spooned onto the chilled plate and returned to the freezer for a minute wrinkles when you nudge it, about 20 minutes.
10. 10
    Ladle boiling water from the canning pot into the bowl with the lids.
11. 11
    Using a jar lifter, remove the sterilized jars from the canning pot, carefully pouring the water from each one back into the pot, and place them upright on a folded towel.
12. 12
    Drain the water off the jar lids.
13. 13
    Ladle the hot jelly into the jars, leaving 1/4 inch headspace at the top.
14. 14
    Use a damp paper towel to wipe the rims of the jars, then put a flat lid and ring on each jar, adjusting the ring so that it's just finger-tight.
15. 15
    Return the jars to the water in the canning pot, making sure the water covers the jars by at least 1 inch.
16. 16
    Bring to a boil, and boil for 5 minutes to process.
17. 17
    Remove the jars to a folded towel and do not disturb for 12 hours.
18. 18
    After 1 hour, check that the lids have sealed by pressing down on the center of each; if it can be pushed down, it hasn't sealed, and the jar should be refrigerated immediately.
19. 19
    Label the sealed jars and store.