The first part of the term is derived from the Swiss German name for hashed potatoes, rösti, which originated in the canton of Bern and is considered typical of Swiss German cuisine.[2]
Graben has both the concrete and abstract meaning of "rift", with the Saane/Sarine river valley in the bilingual canton of Fribourg separating the linguistic areas. The Swiss-French use a similar expression: barrière de rös(ch)ti, literally "rösti barrier", or rideau de rös(ch)ti "rösti curtain" (reminiscent of the Iron Curtain). Just like Röstigraben it has become a familiar facetious expression used whenever differences arise, e.g. different voting results.
By analogy, the term Polentagraben is used to refer to cultural and political differences between Italian-speaking Ticino and German-speaking Switzerland.[3] The canton of Ticino is seen as having a tougher stance towards migrant workers and a greater attachment to the notion of Swissness.[4]