I can be moody sometimes. (I'm not an alcoholic though, if it matters.) I just get quiet and I want to be by myself and read.
But we moody people need to suck it up and jolly ourselves into a good mood when the occasion calls for it, like your planned day out. It's just something we have to train ourselves to do--it's only decent! (And, um, faking a good mood can often lead to an actual good mood.)
If he agreed to an outing and then pouted all day, that's lame. And then if afterwards he "insisted" that you hear him out as he whined that he didn't want to go out in the first place--huh? That's going above and beyond moodiness and veering into manipulative.
Maybe you could have a talk with him along the lines of, "Hey, if you're feeling quiet and want some solitude, just let me know and I'll respect that. But enough with the sulkiness."