Roughly chop the apple’s including the skin and the pips and put in a heavy based pan with the roughly chopped mint and water and gently bring to the boil, continue to boil gently until the apples are cooked and soft about 20 minutes. Mash the cooked apples and add vinegar and simmer for a further 20 minutes.
Collect the clear liquid by straining through a muslin cloth (this will take a while, maybe even overnight?).
Add the sugar to the liquid back in the cleaned heavy based pot and bring back to a gently simmer until the jelly reaches setting point, this could take 10 minutes to 3 hours depending on the size of your batch and the pectin levels in the fruit.
Skim any scum from the top by laying paper towel on top to collect it.
It has reached setting point when you put a sample on a cold plate and the sample is firm in the fridge.
Pour into hot sterilized jars and seal. This should make about 5, 300 ml jars