A junk achievement for drinking vinegar, one of dozens paying out only common Adventurer boxes.
Kombucha! is one of the two examples Carl gives of the stupid achievements that made up the vast majority of the fifty-plus item backlog he clears during The Ceasefire. He earned it for drinking vinegar — a detail tied to Tserendolgor, the "vinegar goddess lady" of the previous floor. Alongside Stretching!, it garnered him nothing better than dozens of bronze and silver Adventurer Boxes.
Filler achievement from Carl's vinegar-drinking on the previous floor.