When we taste tea, there’s far more to the physical experience than just tasting flavors. The complex compounds and elements that make up our tea change the way we perceive our brewed leaves. How do we describe what we feel and what causes these sensations? There’s a lot to get into in this topic at large, but for today we’re focusing on that feeling of dryness some teas give us in our mouths and what causes them: tannins… or, are they?
Tannins and Catechins are Both Polyphenols
Tannins are a naturally occurring polyphenol (a compound) found in many plants, seeds, leaves, peels, flowers, and woods. They are derived from phenolic acids, sometimes called tannic acid, and are large molecules that bind willingly with proteins, cellulose, starches, and minerals. Often you hear wine enthusiasts talk about tannins in wine, especially red wines.
Tannins are not the only type of polyphenol, and while for a long time people thought that the same dry mouth sensation you get in dark teas and dark wines were both tannins; turns out that’s not true. Catechins are the culprit for this sensation in tea, whereas the same sensation in wine comes from the tannins. Catechins are another phenolic compound, that are abundant in tea.
In common terms when people talk about that drying sensation, it’s often still referred to as tannins or a tannic mouth feel. So, today the word tannin both describes the actual polyphenol as well as the sensation. With this in mind, when we talk about tannins as in the compound, that’s not found in tea (catechins are). But, when we talk about a tannic taste, that’s felt in tea.
The two are so seemingly interchangeable, that when people are being trained to become wine Sommeliers, teachers will use very strong black tea to teach their students what tannins (and subsequently catechins) will do to the mouthfeel. And when tea students are being taught how to identify the same feeling, teachers will use red wine for reference.
The word tannin originally referred to “crushed oak bars containing tannin” which were part of the process to convert animal hides into leather. This is where the ancient technique of ‘tanning’ was coined. The Chinese, Greeks, and Romans all historically used formulations of plant tannins in this way. You would not be able to ‘tan’ leather with catechins from tea in this same way.
What Do “Tannins” Taste Like?
Have you ever had a drying sensation in your mouth after drinking a tea? That’s the “tannins”! We often attribute the balance of a rounded tannic feeling to high quality tea making. Tea is about complexity and balance. The tannic sensation adds to the complexity and stimulation of the tea drinking experience but, if a tea is overly tannic, that’s a negative trait. One of the reasons we feel the dryness we do is because the polyphenols are grabbing the protein from our mouth and binding as we sip.
We can, to some degree, manage the tannin content through brewing. The tannic feeling tends to leak out the longer you let a tea steep. So longer steep times can give you that “over-brewed” taste, which may be attributed to an over extracted amount of polyphenols.
In some plants, the bitter or astringent taste from these polyphenols function as a defense mechanism. For example, unripened fruits are high in tannins. This is a natural way for the plant to discourage animals from eating fruits as they are still maturing. Once they are ripened and ready to drop, so does the level of tannins. In tea, we enjoy the complexity that these “tannins” bring to the drinking experience. Balanced notes of astringency from tannins can be seen as desirable and intentional.
On a molecular level, catechins have a smaller structure than tannins. When we process tea, we break down the molecule structure even further, which gives you a ‘finer tannins’ mouth feel. The finer tannic feeling give sun a more rounded sensation and are highly desirable because it balances that line of complexity. EGCGs are a larger type of catechin than EGCs, both able to be broken down further in the tea making process.
What Teas Are Highly Tannic?
Often people think they don’t like pu er tea because they have only experiences ones that aren’t made well. With better making, the tannic experience is more pleasant and it gives us a structured mouth feel, but is far more rounded. It’s always fun for us at the tea house to see people who have previously thought of pu er tea to be “too astringent” to experience what a well made, rounded pu er tastes like and how delightful the complexity of the “tannins” can be.
If you’re pairing your tea with foods, highly tannic teas tend to go great with rich, fatty foods, just like a red wine would. The added astringency and dryness cuts through the intensity of those food flavors beautifully. The polyphenols also catch on to the proteins, so with these kinds of food it causes incredible sensations in our mouths.
Polyphenols are a natural antioxidant and are found to fight inflammation, so drinking them is a strong benefit of tea to our bodies! Catechins are a milder “tannin”, so for those who might get tannin headaches from wine are less likely to with teas.
Teas To Try To Experience “Tannins” In Tea
Our Qi Lan is a great example of a Yan Cha Wu Long (cliff tea) that is very tannic, but also has a very strong aroma and aftertaste that balance out the tannins. This is what we look for in good tea making, the complex balance of all the elements to create a full body sensational experience.