1TBSPPectinIf using 'Jam Sugar' you won't need this extra pectin. Pectin comes in powder and liquid form. See recipe for instructions.
Clean and sterilize your preserving jars. Run them through the dishwasher or place them in the oven at 270°F (130°C) for 20 minutes and then let them cool. Inspect them for any cracks or imperfections and discard any that aren't perfect. The lids can go in the dishwasher too or you can pour scalding water over them and leave them in it for five minutes before repeating. Allow them to fully air-dry before you use them to seal your jars.
Put a plate in the freezer in preparation for testing the setting point.
Rinse the berries and then pluck the berries off the stems. The stems leave a bitter taste to your preserves so try to remove as many of them as possible but don’t stress out if you don’t get all of them. To get the berries off, you can use a fork to pull them off the stems but what I like to do now is gently roll and pull them off with my fingers. I place the entire cluster of berries in my hand and gently tug the berries off.
Place the berries into a large saucepan with the water and bring it to a boil. Lower the heat to a simmer then when the fruit is soft use a potato masher to squish the berries.
Set up your jelly strainer over a bowl and pour the berries and juice through it. Leave the berries to drip for at least a few hours if not overnight. You’ll notice in my photo that I’m using a jelly-straining frame but a piece of muslin to strain my berries.
Measure the juice you have after it’s been strained and discard (compost) the berry solids. You need 1 kg of juice for this recipe -- about 1 liter or 4.25 cups. If you have less, top up the juice with water to the amount needed.
You will need 1 TBSP powdered pectin for this recipe, or 2 TBSP liquid pectin.
Place your jars and lids into the oven and begin warming them on the lowest setting.
If using powdered pectin, place it into a small pan with 3 TBSP of water. Heat to a boil and still until the pectin is completely dissolved. Using pectin that comes in a liquid form does not require this step.
While the pectin is dissolving, Heat the juice, sugar, and lemon juice in a pan. Add the pectin once it's dissolved and stir well. Bring the juice to a rapid boil and leave it there until the setting point is reached. This will take about 15-30 minutes of boiling and you should keep a close eye on it, stirring
Check to see that the setting point has been reached by dribbling a small amount of the juice onto the plate you’ve chilled in the freezer. Leave it for a minute and then push at it from the edge with your fingertip. If the jelly crinkles up, then the setting point has been met and you can move on to step 8. If it just moves aside in a liquidy way and without any crinkling then continue boiling.
Turn the heat off and let the pan sit for a couple of minutes until a skin forms on the surface of the jelly. Skim this off with a spoon and discard then pour the jelly into the warm jars using a jam funnel. Fill to within a quarter-inch of the rim and twist on the lids or lids and rings.
Water-bath the jars to ensure that they're fully sterilized*. Fill a tall pan with water and place either a rack at the bottom. Bring to a boil then lower your jars in so that they're not touching and that there's at least an inch of water above. Bring back to a rolling boil and leave the jars in the boiling water for five minutes. Lift them out vertically (not tilted) with a jar lifter and set them on the counter to cool. The lids will seal as the jelly cools – you’ll hear a pop as the seal closes. It may take twelve or more hours for the seal to take.
Store the jam for up to a year in a cool cupboard. Once open, refrigerate, and use within six months.
In Britain, it's not common for people to water-bath high-acid preserves like this elderberry jelly. It's much safer if you do though since it will ensure that the contents are sterile. You can read more on the topic here.