Keep stirring until the blackberries and pectin mixture reaches a rolling boil.
(A rolling boil can not be stirred away)
At this point, you want to add all of the sugar at once and stir it in completely.
Keep stirring until the mixture reaches another rolling boil. Set your timer for ONE minute.
(You do not want it to boil for longer than a minute because that might turn your preserves into hard candy.)
Once the minute is up, turn off the heat and keep stirring until it cools down a bit and stops boiling. If you are cooking on an electric stove, completely remove the pan from the burner. If any foam has formed on the top, remove it with a metal spoon.
Lift the empty jars out of the water bath canner and put them on a towel or cooling rack on your counter or table.
NEVER put a hot jar on a cold surface because your jars can easily break if you do.
You can pour the hot water from inside one or two of the jars over your lids to help soften the rubber seals.
Ladle the blackberry preserves into the jars, leaving about 1/4" of empty or "head" space at the top of each jar.
Using a damp towel or damp paper towel, wipe the top of each jar to make sure they are clean.
An unclean jar top is one of the most common reasons for jars failing to seal properly.
Put a lid and ring on each jar, and tighten them just finger tight.
Put each jar into the water bath canner, being sure that they aren't touching each other, and process them for 10 minutes.
Once the 10 minutes have passed, lift the jars out of the water and set them on a towel or cooling rack. You should start hearing the pings of the jars starting to seal. *Fun Game* Yell excitedly each time you hear that sweet ping!
Leave the jars for 24 hours to cool and seal. Your homemade blackberry preserves will last for a year or more if stored properly out of direct sunlight. Once a jar is opened or if any failed to seal, you can keep them in the fridge for up to a month.
