How long doeas it takes for mushrooms to go bad?
Hmm, I’d say a week, maybe?
they can keep longer if you keep them in a paper bag with paper towels to absorb moisture. the variety of mushroom matters as well. shitakes and chanterelles can keep for quite a while, as will your common button and crimini mushrooms, while something fragile like an oyster mushroom is going to get overcome with moisture more quickly.