Ariadne came to realize that Arthur's taste in drinks was not only an effective barometer of his mood, it was also an astonishingly accurate forecast of how he would act once he'd downed a few.
Whiskey - rye, more often than than not - was what he drank when he was in what Eames referred to as "sad bastard" mode, when his innate tendencies towards noir and pretentiousness won out and he wanted to sit alone on his bar stool and sip one drink for hours and ponder the weight of the world and the many terrible things he'd done. If she'd known then what she knew now, Ariadne would have spotted the amber in his glass at the hotel bar in LA and not bothered trying to sit down next to him. As it was, he'd listened to her attempts to start a conversation - about what they'd done, about what she'd seen in Limbo - with tired eyes and brushed his fingers against her cheek and sent her away. It was his second drink, and by then the whiskey had exacerbated all his silence.
Vodka, on the other hand, was for celebrations. He picked up the habit of downing vodka shots one after another from a chemist he knew in St. Petersburg, apparently, and they went straight to his head and left him bright-eyed and hectic and prone to swift, sudden grins. They also made him reckless. Arthur was drinking vodka the night Ariadne had cajoled him into visiting a club, his collar open and his hair ungreased and brushing her forehead when he looped an arm around her waist and pulled her in for a long, messy kiss. He never properly answered her when she asked if he ever would have done it without the vodka coursing through his system, but she was bemused and grateful nonetheless.
He would drink wine with her on normal days, teasing her gently about her Francophile ways as he uncorked a bottle of red to go with dinner and sipping at a glass of white on long summer afternoons, but he always drank beer when the Cubs were playing a game that he had to watch on various illegal streaming television websites. And it was always cheap swill, the sort that she'd stopped drinking after freshman year of college, and while he may have sipped approvingly at the craft beer and microbrewery bottles she foisted on him he always went back to the sort of stuff she mentally associated with frat parties and underage drinkers.
Gin, he informed her quite seriously one evening, was like drinking perfume. He may have only said this to provoke Eames, who sang the glories of his native drink. Rum was reserved for summer with lots of fruit and an oscillating fan pointed at their bed, brandy was for Christmas and putting in sweet drinks and the occasional brandy Alexander, which she found hilarious for reasons she couldn't explain.
And tequila... well, after the first time Ariadne could never think of it without blushing furiously and temporarily losing the power of speech.