The apples should definitely be sour, firm and very aromatic, something that is still unripe is also important. My favorite varieties: Cox Orange, Goldparmäne, Jonathan. The addition of a quince is recommended, if not possible or desired, then take 2 more apples. Of course, everything without a core house. If these fruit specifications are adhered to, the liqueur succeeds without reworking.
All ingredients come in a large glass with a cap. The approach is agitated or stirred more often and has to stand for 6 weeks. To have a comparison, you can also add the rum after filtering.
Then it is filtered, possibly a little more sugar, but carefully, test one day, check the next. Another addition of wine (or apple juice) is also possible. Then fill it up, and be patient again.