Wash the peaches, cut into small pieces and puree with the peel.
Add the preserving sugar, bring the mixture to the boil on the stove and let it simmer for about four minutes.
Then skim off the foam and do the gelation test. If the jam becomes firm, add the Prosecco and stir.
Immediately pour the hot jam into jars, close the jars immediately and turn them upside down on a wet tea towel for about 30 minutes, then turn them over again.