There's citric acid in a lot of sodas anyway... anything supposedly citrus, I think. It makes things a bit tart and is also... a preservative? I think.

I'm really tempted to take my candied ginger (I always have some around, and it's just ginger and cane sugar) and get all empirical about this. There's Coke in the house all the time, and the husband could sacrifice some in the name of science... no other soda, though.

Can you get Reed's Ginger Brew in Montana? If not I might have to send you some.