Green’s Dictionary of Slang

(orig. US) to become hostile towards.

1862		Rocky Mountain News 20 Nov. n.p.: Guess the M.P. will ‘sour’ on William C [DA].
1876		(con. c.1840) ‘Mark Twain’ Tom Sawyer 256: I don’t want ’em [i.e. criminals] souring on me and doing me mean tricks.
1906		S. Ford Shorty McCabe 69: He accumulated a sort of ingrowin’ grouch and soured on the whole push.
1926		Wood & Goddard Dict. Amer. Sl.