Coca cola has been brought on the table for aya brewing ( don't remember whom now ). We argued that indeed, as Jess pointed the phosphoric acid was supposedly a help in extraction, the rest, I would be better be off with nice juices such as grapes ). Next time, am brewing with grape juice and reduce down to solid. The sugar with tannins will caramelize and make a thick and sweet paste.
AM not a big fan of Coca cola, and to be honest, when I read the title, I was more up for discussing tek to DIY you real "coca cola" from cola nuts and coca leaf.
Well, that's another interesting topic.