i just attempted to make my first batch of homebrew stout and i believe i may have screwed it up completely. it started at 1.050 gravity and is supposed to be at 1.012 - 1.016 final gravity and it has stayed at 1.031 gravity over the past two-three weeks. i went back to the store and got some more yeast and put it in, but it still hasn't changed. i didn't even see any activity in the airlock when i put in the fresh yeast. so i'm wondering what i should do. should i go ahead and bottle it or is there something more that i can try adding for it to become the correct gravity? or is it now useless and completely screwed up? please help!