You're both somewhat correct. Although I doubt it'll ever matter to the game in a major way, most food in the setting is either scavenged from pre-disaster ruins, or fresh-created stuff. The fresh stuff is mostly either nasty but nutritionally-balanced paste, or extremely questionable street food ala Demolition Man (remember the fried rat the one vendor sells). Pre-disaster society had absurdly good preservation tech, as evidenced by the burger description, so there's still a lot of that to find in the ruins, but it's still somewhat rare and requires work and risk to dig up, so it's more of a delicacy for the rich (with the possible exception of a few items, like the hamburger, that were SO mass-produced they're everywhere). Alcohol keeps well anyway (well, some of it), but I'd guess the bars are stocked with a mix of dug up relics and fresh stuff, since booze, like drugs, probably commands a high enough profit margin to make hydroponics and grow operations worthwhile, especially in The Gutter. Quality and ingredients are obviously going to go down outside of there though; most of what Havens sell is probably only slightly better than moonshine.
Figured it was either high proof but questionable or Mezz was a lightweight considering how easy it is to get him blackout drunk or slutting it up in the host club lol .
Related note, working on some fan cocktails based on the games. Got a couple that aren't finalized yet but when they are I'll have the specs on FA and link to it in the fanart chat I guess.