From gin (“Australian aboriginal woman”) + piss (“inferior alcoholic beverage”).
gin’s piss (uncountable)
- (Australia, slang) Poor quality beer.
1998 September 29, AG, “A Winnah-Beck's Bier, Pretzels and Pinball!”, in rec.games.pinball, Usenet:
As we Aussies would say a seppo beer like Coors tastes like gin's piss (you don't wanna know!) compared to ours - would you like some beer with your rocky mountain water!
2002 October 28, tediboy, “Labatt Blue vs. Molson Canadian”, in alt.beer, Usenet:
Both sound like some sort of Canadian/North American gin's piss but I believe they are reasonable facsimiles of beer as we know it in the Antipodes, so I definitely would go the nearest.
2004 July 25, Teotwawki, “Titles for Scurvy's Life Story”, in alt.music.deep-purple, Usenet:
but he wears a nice hat tho, for whatever that's worth.
a flagon of drunken gin′s piss p'raps ?