Apple tree ID

[LillyLeaf]

Any idea what this apple tree is? Not sure when to pick the fruit. They are very bitter so guessing they are cooking apples. Photos was taken today. Some are all green while some are half red where exposed to the sun. Thanks

How big is the tree? If it's huge then it could be a Bramley, but there are zillions of apple varieties and we need more to go on.

Have a look at this site and see if anything looks familiar.
https://www.orangepippintrees.co.uk/trees/apple-trees

This site might help too.
https://www.orangepippin.com/search.aspx

They are sour because they aren't ripe yet. Only a few varieties are ready for picking by early August, and most aren't ripe until September onwards.

Pick them when they come off easily with a quarter turn.

Then take one to a local apple day (ususally late September, a garden centres plant fairs or National Trust places) for ID.

They look very matte in the photos, which is usually a sign they are a long way from ripe. Don't even try picking until the skin has a bit of gloss.

Mine are similar to this, I don’t pick them until at least end of September in the north and despite being an eating apple
(Royal Gala) it’s very rare I get one that’s has ripened to a point where it’s edible from the tree.

Mine do however stew down beautifully and because they are a bit tart they make wonderful crumbles
and apple sauce and sponge puddings.

No!! Pick when they come off if you lift them gently in your hand.

I suppose that’s not so far from a quarter turn. But they definitely shouldn’t need a half turn

Don't even try picking until the skin has a bit of gloss. Some apples never acquire gloss. Russet apples stay matte, and some non-russet apples have barely any shine

Most apples need picking between late September and end October, and some of the later ones need to be left to ripen in storage.

These don't look like russets.

I don't know, that could be a bit of russeting on the red bit. They're clearly not Egremont Russet or similar, but apples can have a bit of russeting and that will affect its final look, like this example