Cut the pitted peaches together with the skin into small pieces and place in a large saucepan.
Scrape out the vanilla pod and mix the pulp into the peach pieces.
Stir in the preserving sugar and let everything stand for about 1-3 hours (the longer the rest time, the softer the pieces of fruit will be later, 1 hour was enough for me).
Add a little squirt of lemon juice before boiling.
Bring to the boil while stirring, then let it simmer for at least 4 minutes while stirring constantly.
After a successful gel test, fill immediately into hot-rinsed jars.
Turn the glasses upside down and let stand upside down for 10 minutes.
The vanilla pod gives the jam a soft note, which means that the possibly bitter peach skin is no longer of any consequence in terms of taste.