From Yiddish, rendered chicken or goose fat. in east European cooking chicken fat is used as an easy fix to otherwise tasteless cooking. in other words, its a Crowd pleaser.
in jewish slang, Schmalts refers to a tacky, overdone or outright exploitative piece of art or design.
Goyim: hi man, have you seen that food-porn video where they use lard in a matzo-ball soup? i thoughtyou guys don't eat pork.
jew: that's just Schmaltz.
A person who is a bad actor, actor who indicates, over-the-top, could potentially be overacting to make moments larger than they honestly feel about them.
A shitty acting performance, or a schmuck who is unsuccessfully trying to act
Schmuck + acting = schmacting
The actor had no connection to the work, it was obvious he was schmacting.
Watching that scene was so painful, the actor clearly had no idea how they truly felt and was indicating an emotion, clearly a very bad case of schmacting.
You think that was a performance? Acting, schmacting.