Does Coffee Have Tannins? (Are They Harmful?)

Tannins are organic compounds that are found in most plant-based foods like tea, wine, and even coffee. And the stains that these drinks leave behind on our teeth, mugs, clothes, etc are all because of tannins present in the coffee. Plus the astringent taste and dry dusty feeling of over-extracted coffee, all come from tannins in coffee.

If you drink coffee or tea or wine every single day, you’re no stranger to the stains on a freshly worn white shirt or your counter. The natural compound tannin found in these drinks is the one to blame. So in this article let’s find out more about coffee and tannins and what actually is the purpose of this organic compound.  

Let’s dig in deep.

Are Tannins In Coffee Harmful?

Coffee contains tannin which is responsible for its astringent taste. High doses of tannins in your diet can be lethal and cause severe symptoms like liver damage, nausea, dizziness, and an irritated stomach overall.

coffee on top of ground coffee

Before diving into whether tannin is harmful or not, let’s first discuss what they are.

Tannins are a group of organic compounds that are found naturally in many plants like grapes and teas, these groups of compounds are usually referred to as polyphenols.

Polyphenols act as antioxidants and help our bodies fight toxins. But some don’t. If we narrow it down, tannins are substances that bind with proteins instantly. Therefore, it’s hard to specify what they are but we can understand their nature. Unlike other molecules, tannins can bind to proteins in different ways, meaning that there is no set chemical structure for tannins.

Fun fact, oak bark is known as tannin traditional Celtic languages, from which tannin is named. Tannins originated from compounds used for tanning leather skins in traditional leather production. Tanning leather with oak bark was a very common method of tanning leather.

So are tannins in coffee harmful?

You see, low or moderate doses of tannin or tannic acid have been used for centuries for dyeing and for treating diarrhea. This naturally found chemical compound in coffee is found in very low concentrations. And generally, tannins are not good or bad for your body. They do act as antioxidants but if tannin is consumed in really high doses which are above 50 then it’s lethal.

Symptoms may include:

  • Liver damage
  • Nausea
  • Constipation
  • Irritated stomach
  • Dizziness

Therefore, tannins in coffee are not good nor bad for your body only if not consumed more than 50 g in total.

What Type Of Coffee Has The Lowest Tannins?

The darker roast coffees and the low acid coffees both have less tannin content. Tannin is found in chlorogenic acid which gets burnt off as the roasting takes longer and the majority of the acids are extracted from the coffee.

Coffee is a drink that is an all-natural compound. Caffeine and chlorogenic acid are the most abundant compounds. The raw coffee beans which are also green beans contain 90% of these compounds. But the coffee that we know and are familiar with is not made of green beans without them being processed. In order to make them useful, green coffee is roasted.

The roasting process transforms the raw coffee beans into the coffee that we all know and love. Each level of roast has its own flavor profile and aroma. The three main roast types are light, medium, and dark.

a spilled bowl of dark roast coffee beans

You see, at each roast level, the temperature rises, and the chemical compounds are burning off producing desired results. The chlorogenic acid which contains tannins would be in less concentration in dark roasts. Because the lighter the roast, the less time it has been heated thus very little quantity of tannin would be burned off.

Another coffee that has lower tannin content would be low acid coffee. Since there are many kinds of coffee, people who can tolerate the acidic levels of coffee, tend to choose low acid coffees. Low acid coffees are very common and can be found in markets everywhere. You see, when manufacturers draw out the acid which is chlorogenic acid, the tannin automatically gets drawn out.

Therefore, dark roasted coffees and lower acid coffees are both your best choice for reduced tannin content.

Here I’ve prepared a table of the best low acid coffees that you can enjoy with their respective caffeine content mentioned.

Low Acid CoffeesCaffeine Content
Lifeboost Coffee Organic Medium Roast89 mg to 95 mg
Volcanica Low Acid Coffee Blend75 mg to 85 mg
Java Planet70 mg to 80 mg
Lucy Jo’s Coffee 80 mg to 90 mg
Tieman’s Fusion Coffee85 mg to 95 mg

Do Tannins Stain Our Teeth?

Any foods that are rich in tannins like tea, coffee, and wine can easily stain your teeth. This happens because it can easily bind to the proteins in our teeth.

Though as discussed above, there are no benefits nor anything negative associated with tannins as a whole, one noticeable bad effect of tannin is that it stains your teeth. Have you noticed people who drink a lot of wine have yellow teeth? That’s because of the tannins.

You see, in ancient times tannins were used as a dye, so it’s very evident that they can dye things just like teeth. The tannin is able to stain your teeth no matter what the source is, whether tea, coffee, or wine. Many proteins that dissolve in water precipitate when tannins bind to them, causing them to precipitate. Now precipitation is the process by which a dissolved, freely moving liquid becomes solid and reverts to its original form.

And when tannins hit your teeth, they form complex tannin-protein molecules. These tannin-protein complexes precipitate on the surface of the teeth’s enamel when the tannins in wine, tea, and coffee precipitate thin layers of them.

For learning more about coffee’s effect on teeth you can watch this awesome video too.

How Do You Prevent Coffee From Staining Your Teeth? 

The best way to prevent coffee from staining your teeth is to cut back on tannin-enriched foods. But if you can’t do that all you need to do is use a whitening toothpaste, use a straw to drink, and sip water with chockers.

Tannins are responsible for staining teeth. But you don’t need to worry because the tannin stains on your teeth are not permanent. Hoorah! They do take time to get back to their original white color but it’s definitely not impossible.

Firstly try to avoid tannin-concentrated foods but if you can’t here are three tips for you to follow.

Whitening Toothpaste

Using a whitening toothpaste rather than regular toothpaste can also prevent coffee from staining your teeth. Besides whitening your teeth, these kinds of toothpaste also strengthen your enamel. These contain whitening agents like bleach that gradually remove the yellow or brown tan left from tannin. And you can choose to pick whitening toothpaste over whitening strips which are a bit harsher. So, to prevent coffee stains on your teeth, brush twice a day with these types of toothpaste.

a picture of open mouth smile

Drink Coffee With Water

If you drink coffee with water, you can avoid staining your teeth. A lot of celebrities drink coffee with water. Immediately after you take a sip of your coffee, you take a sip of water. Water will wash away the coffee particles and allow you to enjoy your coffee without any staining on your beloved pearly whites.

Always Drink From A Straw

Drinking coffee with a straw is the most efficient and effective way to protect your teeth from further damage. Essentially, it prevents your teeth from being in contact with drinks that are filled with tannins. As a result, staining is reduced.

Final Thoughts

Tannins are natural compounds that are found in many foods. They bind to proteins and give coffee its astringent taste. Coffee is an organic beverage that has a lot going on. You see in ancient times tannins were used to dye leather and even treat diarrhea.

But in today’s day and age, they have no good or bad effect on humans. Some do act as antioxidants in coffee but it can certainly be harmful if consumed in higher quantities.

Dark roast coffees and low acid coffees have lower tannins so drink those if you are avoiding tannins. Plus, tannins can certainly stain your teeth, and if you are looking to remove stains try to use a straw or brush your teeth with whitening toothpaste.

Marty Spargo

Caffeine aficionado and coffee student (if there's such a thing!). I've come to love coffee in recent years and share what I learn along the way on this website.

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