We live in Walnut Creek California
We planted an (Dwarf?) orange tree several years ago.
It is bearing an immense amount of fruit
but the oranges are VERY VERY sour, even if you leave them on the tree
til they are deep orange. It doens't matter how long they stay on the
tree
They are not edible.

Is there anything we can do to make them edible?
Even for next season?

Thanks
Glenn L