Why is there a residual taste of the fizzy drink it contained (e.g. Mountain Dew) when reusing rinsed plastic bottles for the first few times?

Question

Why is there a residual taste of the fizzy drink it contained (e.g. Mountain Dew) when reusing rinsed plastic bottles for the first few times?

In: Chemistry

Answer 1

Same reason tupperware becomes semi-permanently stained by tomato sauce, plastic is permeable to an extent (which varies depending on the type of plastic and molecules it’s being exposed to), artificial flavouring molecules are absorbed into the plastic during the time it’s in contact with a highly saturated solution (the soda) then released when it comes in contact with a less saturated solution (the water)