Why Does Toothpaste Make Orange Juice Taste Bitter?

Two things we all learn at a young age are that you should never drink orange juice or milk shortly after you brush your teeth. Doing so leaves a horrific result on your taste buds that you never forget all the way through adulthood.

Have you ever wanted to know why toothpaste makes orange juice taste so badly?  The American Chemical Society has the answer for you. They have created a delightful video series called Bytesize Science, and their latest episode illustrates why this bad-tasting phenomenon occurs.

The episode explains that the primary ingredients in toothpaste contain a detergent called sodium lauryl sulfate (SLS). SLS is the chemical agent that creates the foam while brushing, and it happens to influence how your own personal chemical sensors (the 10,000 taste buds in your mouth) taste food.

You all most likely remember learning in school that your taste buds are divided into specific regions on your tongue that taste sweet, salt, sour, bitter, and umami (brothy or meaty flavor recently highlighted in popular cooking shows and networks). SLS affects which of these receptors respond to what you eat and drink.

And that’s all the spoilers to the video we’ll provide. Take a gander for yourself and see exactly how SLS affects your sense of taste.