Does anyone know what Jack Shephard's choice of drink is in 'Through The Looking Gl'?

I know this may be viewed as an immature question, but it's just something I am curious about. It looks like he's drinking vodka ginger ales, or champagne in the airplane? But when he's in his apartment it looks like the same drink but in a 2-6, so I began to think he was drinking tequila straight, or something. Which would be ridiculous unless I have the wrong drink. Any ideas? It looks too light/yellowish to be liquor or whiskey.