Backwash Experiments


Saliva might not be the grossest human fluid, but it is still pretty foul.

One particularly undesirable brand of spit is known as “backwash”. Backwash is the term for fluid which makes its way from ones mouth back into a beverage container.

Backwash seems inevitable. There are some people who believe that the final 10%-33% of liquid in a soda can is backwash.

Can backwash be prevented, and are some beverage containers backwash-proof? One evening, we endeavored to find the truth with a simple test…


To perform this experiment, they basically put dried Kool-Aid in their mouth and went from there.

What did they find out?

We had expected to discover that certain containers were more susceptible to backwash than others. There was some evidence supporting that, with the aluminum can and drinking straw coming to light as the worst offenders.

More significant, it turns out, is the attention and skill of the drinker. If the courteous drinker is actively working to limit his or her backwash, spit transfer can be held to an absolute minimum.

This entry was posted in Uncategorized. Bookmark the permalink.

Comments are closed.