Tannin! What Are They Good For? Absolutely Everything in Tea!

Remember those moments where you took a sip of tea and puckered your lips? That bitter and astringent taste lasting on your tongue afterwards. That flavor comes from tannin in the tea! Tannin cause the flavors of bitterness in your tea and are known for the calming affect after drinking a cup of brewed tea.

Tannin are found in plant/bark tissue, which means it’s an organic compound. Tannoids are a class of polyphenolic biomolecules that bind and precipitate proteins and other organic material. That just means that proteins in a solution are “taken out” of the solution… picture this….

flavan-3-ol (tannin)
Image result for precipitation reaction
Precipitation Reaction

Before we drink tannin, they are a biomolecule that protects plants. The astringent taste that tannin produce is a natural pesticide for plants. It helps prevent being consumed by animals. Now ain’t that teatastic!

Now… Lets get down to business! We’ve learned that 1) we drink tannin in tea. 2) these polyphenolic biomolecules give that astringent taste and calming affect after a cup of tea. 3) the compound we are drinking in tea is the flavan-3-ols. In addition, flavan-3-ols are derived from the tea plant, Camellia sinensis.

Drinking tannin is an involved process. The amount of tannin we consume in tea depends on the type of tea, steeping length, and coloration. The first compound to steep out of tea is caffeine and then tannin and theanine. This indicates that the longer the steep the more bitter the cup will taste because of accumulative tannin biomolecules.

Remember after that first sip of an astringent tea that you are drinking caffeine, TANNIN, and theanine compounds. And that’s why you wake up with a smile or go to sleep calmly!


  1. https://en.wikipedia.org/wiki/Tannin
  2. https://www.livestrong.com/article/527907-tannin-levels-in-teas/
  3. https://www.austinchronicle.com/columns/2004-04-30/208400/
  4. https://en.wikipedia.org/wiki/Flavan-3-ol