Green’s Dictionary of Slang

(US) burnt rum with a piece of butter, ‘an American remedy for a cold’ (Grose, 1785).

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1857		Putnam’s Mag. Sept. 486: While I stirred the ‘stewed Quaker’ that I was cooking for Uncle Payne’s cold [etc].
1869		Dly Milwaukee News (WI) 3 Jan. 4/4: I’ve got a bad cold; I want to stew it with butter and vinegar; and make some stewed Quaker.
1874		Winfield Courier (KS) 26 Nov. 1/6: I took all sodrts of remdies [...] stewed Quaker, hoar-hound syrup [etc].
1889		Fort Wayne Sentinel (IN) 27 Mar. 4/3: She will feed her croupy children on stewed Quaker.
1892		Buffalo Eve. News (NY) 14 Nov. 3/3: For colds, an old-time remedy with a ridiculous name, is a stewed Quaker molasses posset.
1906		Springviulle Jrnl (NY) 18 Jan. 2/3: Molasses posset. commonly called ‘stewed Quaker’ is a fine remedy for a cold.
1933		Adams Co. Indep. (Littlestown, PA) 29 June 2/3: ‘Stewed Quaker’ [...] taken hot was a sovereign remedy for children’s colds!
1950		Atlanta Constitution (GA) 4 Dec. 11/3: It is a preparation [...] called by the common people a ‘stewed quaker’.
1969		Lebanon Exp. (OR) 15 Dec. 3/4: The lady editor observed that ‘this preparation is [...] called a stewed Quaker’.
1973		Lincoln Star (NE) 15 Apr. 3H/2: For extreme cases of sniffles, Gran mixed up [...] a brew called stewed quaker.