It's a term used for unregulated Sewer oil. Sewer oil barons benefit greatly from the ease of collecting this oil in urban zones. Oil buoyancy pushes it to the surface where the oil is easily collected by legit tax paying refineries. However, unregulated Sewer oil merchants don't pay the Chinese govt Taxes, so these outlaws are stuck with the unfavorable Gutter Oil label.

The first documented report of unregulated sewer oil was in the 1960s, where sewer oil was exported from Japan to Taiwan and then used in food processing.

Most sewer oil is properly refined today and poses no health risk to consumers.
Bernard: Joe was that you in the noodles joint? I thought you were going healthy?

Joe: You mean Kuishimbo? Its a dandy restaurant that serves healthy food

Bernard: Like it or not, they serve overpriced cheap noodles, sugar, lowest quality rice/meat & refined Gutter Oil

Joe: I never heard of the Gutter Oil before, Are you sure about that?

Bernard: All cooking oil merchants use cheap Chinese fillers to cut their oils, those usually contain refined Gutter Oil

Joe: That is illegal

Bernard: Gutter Oil Corporations pay all their taxes, so its 100% legal.

Joe: Damn it everything is a Scam

Bernard: As a citizen/peasant you are expected to pay dearly for everything...
by Felix Jabs Arnold January 9, 2019
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