An Explanation for Why Toothpaste Makes Orange Juice and Everything Else Taste Terrible

In an episode of the SciShow series Quick Questions, host Hank Green explains the chemical reason why toothpaste makes everything taste terrible. The cause of the bad taste is the compound sodium lauryl sulfate and similar compounds in toothpaste. They interfere with the ability to taste sweet things and heighten sensitivity to bitter flavors.

Orange juice is a common example because without the ability to taste sugar, it’s very sour, and it is a common thing people drink in the morning after brushing their teeth.