Let's turn this into a writing question and answer it accordingly:
Nancy Kress, in Beginnings, Middles, & Ends, identified talent with vision. She says that you can learn the craft of writing, but not the vision, because it
comes from everything about you: your experiences, your imagination, your beliefs about the world, your powers of perception, your interests, your sophistication, your previous reading, your soul. Vision, sometimes called talent, is not a teachable attribute.
In short, according to Nancy Kress, you can learn how to write well, but you cannot learn how to find something interesting to write about.
But what does this, which pertains to the act of writing, have to do with the act of reading?
Very simple: Writing is reading. When you write a novel or short story or anything else, what enables you to write well? That you can tell if what you wrote is crap! You read your text, and you know if it is good or needs further rewriting. That is what makes a good writer. A bad writer cannot tell if his text is bad and where it went wrong. He cannot read. He can only type words, and feels his text is finished when he arrives at the end.
As a reader, you need the same writer's talent to tell if a text is good or, if not, what is wrong with it. Only someone who could potentially be a good writer has the talent and vision to discern good writing from bad. It cannot be taught. You have it, or you don't.
Hemingway, Munro, Emerson, and Joyce are not great authors because they write well. Opinions about that will differ. They are great because their writing contains a vision. And any good writer (or reader), although he or she might not enjoy the prose of Ulysses, can recognize and appreaciate that vision.
Now, you might object that different people (or cultures) have different standards or tastes and will not agree on what is a good book. Even master writers will disagree on what is masterful writing. That is true.
Psychological research into human-to-human attraction has long tried to find the common denominator for beauty by calculating the average beautiful face. But the truth is that the average beautiful face is just pleasant, not beautiful. It is, in truth, a bit boring. The individual beautiful face is always more beautiful to the person who likes such a face. It seems that individual taste just varies too much to distill a universal principle of human physical beauty.
But what almost everyone can agree on is what they find ugly. This is not good news for ugly people, but certain facial features are simply not found beautiful by anyone. There is widespread agreement across individuals about what constitutes ugliness.
The same goes for other aesthetic areas, for example writing. There is writing that is not masterful for anyone.
For that reason, I would propose to turn this question around. Instead of asking about mastery – which readers and writers cannot agree on – we should ask about lack of mastery:
How do I distinguish bad writing?
Because that is what ails bad writers: they cannot tell what is wrong with their texts. It may be grammatically correct, even elegantly written, and yet readers are bored instead of inspired. And why is that? The answer remains the same:
That text lacks vision.
There are texts that have vision but bore you because you do not share that vision. But there are no texts that excite anyone and do not have vision.
To not be bad (for everyone) but good (for some) your text needs vision. And vision is talent, and talent cannot be learned.