You guys were so good with the Texas toast question I thought I'd up the info ante.
From Betty Fussell's "I Hear America Cooking":
"[American] Indians fermented maple sap to make a vinegar they called ciwabo, in which they marinated venison and other game."
Has anyone ever heard of this/know trustworthy sources about Native American cooking that might provide confirmation/further insight?
The idea of maple vinegar intrigues me.