The classic measurements are as follows,i used less sugar because I felt it was already sweet enough
For every 8 oz Jam:
Black Grapes – 1 1/3 cups
Sugar 1 2/3 cups
Pectin 1 1/2 Tablespoon
6 cups of black grapes destemmed and washed
1 tablespoon of freshly squeezed lemon juice
1 box fruit pectin(I used sure jell premium fruit pectin)
5 cups Sugar( adjust depending on your sweetness)
1.Sterilize the jars you will be storing in jam by boiling them in hot water and wiping them clean without moisture and keep aside.Do not touch the insides of the jars with your bare hands.
2.Grind the grapes into a fine puree.On a saucepan heat the puree until it reaches a boil and all the foam has disappeared.
Make small quantities so you don’t have to worry about the shelf life of the jam.
All through the recipe,make sure your hands and the utensils beings used are very dry.
You can skip the pectin if making smaller quantities of jam,it will at least stay 3 weeks in the fridge without getting spoilt.
Do not add the pectin powder directly into the boiling jam,mix it into 1/4 cup of cold water and then stir it in.