I've only dumped a few. My second beer ever I got ambitions and tried to brew a Belgian Quad that even a year later was undrinkably solventy. I only drank a few bottles to see as it was aging and ended up dumping almost 2 cases. I had another two that were decent at first, but I horribly oxidized them, and by the last 1/2 case or so were undrinkable, so those got dumped. And then I had a spiced cider that was ill conceived, poorly executed, and awful. That got dumped. Beyond that, I've had a few less than stellar but drinkable beers. Those I usually drink. Not something I'd share with others, but not terrible.