We were recently gifted a few flats of black grapes and having never tasted them before, we found the grape to be good but the skin to be rather thick. Not exactly something we want to snack on. Enter in the decision to make jam. After looking through a few recipes I've decided we needed to just follow some instinct and surge ahead. This site has great pictures though to help you along if you need a visual. Since the grapes didn't slip easily out of their skin we've chosen to start the mash, squishing out the pulp/juice, straining, then composting the skin.
1. gather the equipment: jars, lids, rings, towel to put hot jars on, canning pot filled with water, pot for mixing the jam, wet cloth, funnel, tongs, metal spoon, strainer for the skins/seeds, 1 frozen spoon
2. For this recipe you need 3# Concord grapes and 3c sugar. We might venture into some mixed flavorings if this turns out for us.
3. Put the grapes in a tall pot and squish them slightly with a potato masher. Once the juice is coming out turn the heat on. You want the grapes to be heated all the way through, usually takes about 5-10 minutes. Continue squashing the grapes to get the pulp out. Strain the grapes/juice to remove skin and any seeds.
4. Return the pulp/juice back to the pot and in the sugar. Stir it together and bring to a boil for about 5 minutes. Keep stirring! As it thickens, skim off the foam that forms on the top like it does with the strawberry jam. When it looks thicker, get the spoon from the freezer, spoon some jelly on the back of it. If it drips off you need to cook the jam longer. If it slides off in a smooth sheet then it's ready to put in jars.
5. Ladle the jam into your prepared jars leaving 1/4" space at the top. Using your clean wet cloth, wipe the rim and place a lid on each jar. Place rings on the jars and screw on but not completely tightened. Put the jars into the water bath that is boiling and ready. Process your pint or half pints for 10 minutes. Carefully remove the jars onto a towel to allow them to cool for about 24 hours. You should hear the lids popping as they cool and create suction. Tighten the lids and place in the pantry.