-
1
In an 8-quart pan, combine the blackberries, sugar, and butter.
-
2
Over med-low heat, stirring constantly, heat the mixture until the sugar is completely dissolved.
-
3
Increase heat to med-high and bring the mixture to a full rolling boil; stirring constantly.
-
4
Stir in all the pectin; return mixture to a full rolling boil, stirring constantly.
-
5
Boil, stirring constantly, for 1 minute.
-
6
Remove pan from heat; skim off any foam.
-
7
To prevent the jam from separating in the jars, allow the jam to cool 5 minutes before filling jars.
-
8
Gently stir the jam every minute or so to distribute the fruit.
-
9
Ladle the hot jam into hot jars, leaving 1/4 inch headspace.
-
10
Wipe the jar rims and threads with a clean, damp cloth.
-
11
Cover with hot lids and apply screw rings.
-
12
Process half-pint jars in a 200 water bath for 10 minutes, pint jars for 15 minutes.
-
13
Tip: after cooking blackberry jam, the center white cores of the berries, to which the individual seeds were attached, will rise to the surface of the jam; as you stir the jam during the 5 minute standing period before ladling it into the jars, you may skim off as many of these cores as you can findpurely optional, but recommended if entering this jam in a competition.
-
14
Tip: you may use frozen blackberriesyou will need 2 to 3 (16 oz.)
-
15
bags; do not rinse frozen berries before defrosting, and be sure to add all of the released juice to the pan, or the jam will be too thick.
-
16
Tip: To reduce the quantity of seeds in the jam, sieve about 1/4 of the berry pulp before measuring.
