Stevia plants growing outdoors
Food - Drink
Why Stevia May Make Coffee Taste More Bitter
While stevia performs well as a sugar substitute in certain recipes, and it can even be used to sweeten drinks, there's a reason why it doesn't work when added to coffee.
A raw stevia plant contains compounds that are 200 to 300 times sweeter than sugar. The FDA only permits one of these compounds to be used in food and drink: Reb-A.
Reb-A, which is made into a sweetener and marketed as stevia in the U.S., contains chemicals that trigger your tongue’s sweetness receptors as well as its bitterness receptors.
Since coffee is already bitter, it doesn't pair well with American stevia products. Reb-A amplifies the bitterness of the drink, rather than simply sweetening it like sugar does.
Most stevia products and recipes actually use a blend of stevia and sugar or other sweeteners, but even a smaller amount of Reb-A can make your coffee more bitter than you'd like.