Homemade blackberry jelly is the bomb! In late summer or early autumn, harvest those blackberries and make this unique jelly. Our basic recipe is 100% blackberries—no other fruit—to ensure that unique blackberry flavor. Blackberry jelly goes with everything from toast and tea to a delicious side for cooked meats.
You may also use the following recipe to make elderberry jelly if you have a good and trusted source. Elderberry is called the “Cadillac” of jellies and makes a great gift.
Pour about 2 cups water into a large stainless-steel stock or soup pot. Add berries and crush them with a potato masher one layer at a time. Stirring, bring to a rolling boil, and then turn off heat.
Now line a sieve with damp cheesecloth or place a damp jelly bag over a bowl. Add the berry mixture and let the juice drain into the bowl. Make sure no seeds get through. This should yield about 3½ cups of juice. If you need more liquid, add water.
Pour blackberry juice into a stainless-steel saucepan. Add lemon juice and whisk in pectin. Bring to a boil, stirring to prevent sticking.
Add sugar and butter to prevent foam. Bring back to boil, stirring for 1 minute.
Quickly ladle hot blackberry jelly into 4-hot, sterilized pint jars leaving ¼-inch of headspace. Wipe the rims of the jars and add lids that have been washed and dried. Add screw bands and tighten until fingertip-tight.
Place jars on a rack in boiling water bath canner and make sure they are completely covered with water (1-2 inches above the jars). Cover with lid and bring to a boil. Process ½ pint and 8 oz jelly jars for 10 minutes. Remove canner lid, waiting 5 minutes, then remove the jars to a towel on the counter, and cool for 12 to 24 hours. Test sealing of jars by pressing lightly in center of lid and store jars that have sealed. Any jars that don’t seal may be refrigerated and used.