For the apple jam recipe, you need to make the syrup first. Pour water into sugar, mix and put on low heat. Boil the syrup until thick drops form.
Wash the apples, peel, seeds and cut into small cubes.
Transfer the prepared apples to the syrup and cook for 30 minutes. Add lemon zest, vanilla sugar and citric acid before the end of cooking. Transfer apple jam into jars, cover with tin lids and roll up, or cover with paper and tie with twine.