Why does toothpaste and orange juice taste so bad?!

Toothpaste can make orange juice taste bad because of a chemical reaction that occurs in the mouth. Most toothpaste contains a compound called sodium lauryl sulfate (SLS), which is a foaming agent that helps to clean teeth by removing plaque and debris. SLS can break down the phospholipids in the orange juice, which are responsible for the juice's pleasant taste.

When SLS comes into contact with the phospholipids in orange juice, it breaks them down into their constituent fatty acids. These fatty acids are bitter, and they can overpower the sweet and tangy flavors of the orange juice, making it taste unpleasant.

Additionally, toothpaste often contains mint or other strong flavors that can leave an aftertaste in the mouth. When combined with the bitterness of the fatty acids, this can make the orange juice taste even worse.

To avoid this unpleasant taste, it is recommended that you wait at least 30 minutes after brushing your teeth before consuming acidic beverages like orange juice. This allows your saliva to neutralize the SLS and other toothpaste ingredients in your mouth, reducing the risk of a chemical reaction with the orange juice.