Place a few small saucers in the freezer before you start cooking the jam.
Rinse the concord grapes.
Remove the pulp from the grapes by squeezing one end of the grape (opposite from the stem side). This will pop the pulp right out (see picture in post).
Place the pulp in one bowl, and the skins in a separate bowl.
Mix the pulp, sugar, lemon peel and salt in a saucepan. Cook the pulp for about 5 - 10 minutes, until the it's softened and the sugar is dissolved.
Pass the softened pulp through a sieve to remove the seeds (doesn’t need to be a fine sieve, just small enough to catch all the seeds) and place it back in the saucepan.
The lemon peel will also be caught in the sieve. Remove this and add it back in to the saucepan.
Add the concord grape skins into a blender and add about 1 - 2 cups of the pulp. Blend until smooth.
OPTIONAL - You can pass this grape skin mixture through a sieve as well to have a super smooth jam, but it's not necessary.
Add the concord grape skin mix (sieved or not), to the rest of the pulp in the saucepan.
Cook over medium heat, and bring the mix to a boil. Stir frequently to make sure that the jam doesn't stick to the bottom of the pan.
Cook for about 45 -50 minutes. Do the jelly test (as described below) at around 45 minutes - place a small amount of jam on a freezing cold saucer. Put it back in the freezer for about 1 minute (until the grape jam has cooled down, but not frozen). Then track your finger through the jam to test the consistency.
If the parted jam flows back easily and meets in the middle again, then it’s too runny. A slightly thicker consistency where the jelly/jam flows back a little, but it's slow and doesn't meet in the middle again, is the perfect consistency for me.
If the grape jelly is still a tad too runny, cook for a few minutes longer. Test the jelly every 5 - 10 minutes until you get the desired consistency. Don’t cook for longer than 60 minutes however, as this will overcook the jelly/jam.
Remove the lemon peel, and let the jam cool down slightly.
While the jam is still hot, ladle the jam into hot sterilized jars. Close the jars with sterilized lids, and allow the jam to cool down completely. Store in the fridge overnight, and use AFTER the jam has rested for at least 6 hours.
Store in the fridge for up to 3 months. But once opened use within 2 weeks.