Is there a word/phrase that describes someone flinching after they sip alcohol?
Solution 1:
I believe the word you seek may be "wince". Let me add the word "recoil" which is also fitting.
"After taking a shot of sour apple whiskey, Gus winced at the overwhelming taste."
"After taking a shot of sour apple whiskey, Gus recoiled at the overwhelming taste."
https://www.thefreedictionary.com/wince
https://www.thefreedictionary.com/recoil