Green’s Dictionary of Slang

jerker n.1

[jerk v.2 (6)]
(US)

1. (also soda-juggler) a soda-fountain clerk; usu. as soda-jerker.

[US]G.W. Peck Peck’s Bad Boy and His Pa (1893) 289: A sensitive soda jerker, who has reformed, feels that it is worse than three card monte.
[US]Ade Pink Marsh (1963) 207: I do n’ wan’ no sody-juggleh out o’ no drug-stoah to stan’ round an’ rubbeh when I’m talking.
Lincoln Jrnl Star (NE) 26 June 8/4: Let every American drink deep [...] to His Nibs, the Soda Jerker.
[US]H.E. Rollins ‘A West Texas Word List’ in DN IV:iii 229: soda-jerker, n. A man who dispenses drinks at a soda-fountain.
[US]H.C. Witwer Fighting Blood 5: I had to get a job [...] I landed one as soda jerker.
[US]S.J. Perelman in Marschall That Old Gang o’ Mine (1984) 49: That cheap soda-jerker! My only daughter in love with a soda-fountain!
[US](con. 1920s) J.T. Farrell Judgement Day in Studs Lonigan (1936) 562: ‘Hot roasted peanuts!’ a greasy man, wearing a white soda-jerker’s coat, shouted.
[US]R.O. Boyer Dark Ship 221: He was a soda jerker in Frisco.
[US]Progress-Index (Petersburg, VA) 1 Oct. 19/1: ‘Can I help you?’ asked a soda-jerker.

2. a bartender; in combs. such as whiskey-jerker or beer-jerker under beer n.

[US]B. Harte Gabriel Conroy II 311: Your suggestion, Peter [...] emanates from [...] an intellect weaked by Rum and Gum and the contact of Lager Beer Jerkers.
[US]C. Himes Crazy Kill 95: The club where you work as a whiskey jerker.

3. a drinker; often as beer-jerker under beer n.

[UK]‘William Juniper’ True Drunkard’s Delight 233: A term for a drunkard [...] jerker.