Does Backwash really happen?
![](https://wpsu.psu.edu/wp-content/uploads/2020/09/backwash.jpg)
Does saliva really wash back into the milk carton from your mouth when you take a drink? Test it for yourself using powdered drink mix and see what happens!
Does saliva really wash back into the milk carton from your mouth when you take a drink? Test it for yourself using powdered drink mix and see what happens!