I know what you're talking about too. The alcoholism is the elephant in the living room.
As codependents, we tiptoe around the subject. It's just what we do. Until we turn into shrews over it, that is.
I also think you're doing that thing: don't wanna bring "it" up when he's in a foul mood, because it won't be well received. Don't wanna bring it up when he's in a good mood, cuz it'll wreck his good mood. It's a no-win situation isn't it?
I think what Learn said. Feel the fear or anxiety, and push through it. Your heart is gonna be racing, you're gonna have butterflies in your stomach, you're gonna try to find just the right words so it's loving, gentle, respectful, yet also makes the point that you think there's something wrong. Yes, I know these talks.
I think this particular topic is so difficult for us because of the things it triggers in us.
Good luck, let us know how it went.