Star Trek Discovery: Every Easter Egg & Hidden Reference From 'People Of Earth'
5. That New Drink Synthehol
Forced to blend in with the Discovery crew and don one of their uniforms, Book takes the edge off by having a bunch of drinks in the officer's mess. Michael informs him, though, that he's been drinking synthehol and Book is rightly disappointed.
Synthehol first appeared in Star Trek: The Next Generation and was described as a simulacrum of booze with "intoxicating effects [that] can be easily dismissed".
Unfortunately, Discovery serving synthehol is something of a discontinuity as the TNG episode "Relics" established it as a new invention of the 24th century and something someone from the 23rd century, like Scotty, wouldn't be aware of.