Once the seeds are brown, the apple could be called ripe. The best thing to do is check a few by cutting them open. Then taste a few and see what you think. Of
course this is a matter of taste. Some people like them a little tart and other people like them damn near mushy.
I'm in the same boat of having a lot of old homestead apple trees that drop tons (it could literally be tons) of fruit through the season. Here's how I manage them:
Early drops that are not at all ripe go directly to the pigs.
Fruit with damage from falling thirty feet out of a tree (and hitting all the branches on the way down) is also given to the pigs. I'm talking seriously bruised or cracked skins, anything with big bug, bird or mammal damage.
Fruit that is pest free and without major damage is eaten fresh by the whole family. Leftovers go to the pigs
Fruit that is ripe or past ripe and with minimal damage is used is sauces, jams, butters and juices.
Leftovers from cooking, peeling, coring etc all goes to the pigs.
Since my trees are so huge I can barely reach any of the fruit. I just wait til the apples drop off for the most part. If I were picking them off the tree I would just aim to pick the ones that most resemble the ones I've tested and liked. My apples tend to ripen over the course of a few weeks so I pick the best ones daily and allow the others to stay on til I need them.
So... eat what you can. Preserve what you can't eat fresh and
feed the rest to the pigs.
Then eat the pig.