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Does coffee contain tannins? And are they good for you

Does coffee contain tannins? Where are they found? Are they dangerous, or are there side effects?

We’ll be covering all of this and more. You’ll learn all the essentials about tannins in your coffee.

coffee tannins

Does coffee contain tannins?

Most coffee does indeed contain tannins. Two main factors affect the amount of tannins in your coffee: the type of coffee beans/how long and at how high a temperature the beans were roasted and the brewing method.

1. Types of Coffee

Generally speaking, the lighter the roast and the higher the altitude at which the coffee is grown, the higher the concentration of tannins will be. Coffee grown in soil that is volcanic (and therefore rich in minerals) will also be higher in tannins.

For instance, Arabica beans have less acid than robusta beans, even though arabica beans often taste more acidic. Decaffeinated arabica also has 3-9 percent less acid than regular arabica.

Green coffee beans have minimal acids, but the roasting process increases the tannin levels significantly. Dry roasted coffee has lower levels of tannins than washed coffee (wet-processed coffee).

2. How you Brew

Coffee that is brewed for longer – say more than 10 minutes – has a lower level of tannins than coffee that is brewed for just a few minutes. Dark roasts may taste stronger, but they have less acid.

If you want to brew coffee for lower acid content, try cold brewing. Cold brewing helps reduce acids that are extracted from the coffee.

On a side note, the finer the grind, the higher the level of tannins.

What are tannins?

Tannins are plant compounds that are otherwise known as polyphenols. They are known for bringing a bitter or astringent flavor to foods.

Where they are found

Tannins are naturally present in legumes, nuts, berries, pomegranates, smoked foods, wine, beer, chocolate, and certain herbs and spices.

Are tannins dangerous?

As with most things, excess amounts of tannins can irritate the lining of the stomach and cause vomiting, liver damage, or nausea.

Possible Benefits of Tannins

1. Tannins can have antioxidant effects

Tannins bring antioxidant activity to the body, which some studies say may have potential benefits for fighting cancer and cardiovascular diseases. Tannins are excellent for attacking free radicals, which otherwise might damage cell membranes, which can lead to inflammation.

2. Tannins can have antimicrobial effects

The very fact that tannins bind to iron means that they have been shown to have antimicrobial effects. This is particularly true for inhibiting the growth of gastrointestinal bacteria.

3. But they’re beneficial to gut bacteria at the same time

Tannins help strengthen the barrier formed by the walls of our intestines. This means syndromes such as leaky gut have less chance to take hold. Tannins have also been found to reduce inflammatory stress in the colon.

Drawbacks of Tannins

1. Lowers the amount of iron you can absorb

Some studies have shown that tannins can affect the body’s ability to absorb iron, leading to an iron deficiency. However, it would seem that people whose iron absorption is most affected are those who already have low stores of iron in the body.

If iron levels are a concern for you, you can take iron supplements to counteract iron reduction due to tannins. You can also eat or drink items rich in vitamin C while consuming tannins, as vitamin C helps us absorb more iron from the foods we eat.

2. Bitter taste

Tannins do bring a bitter taste to your coffee. However, you can impact on this by adding a pinch of salt to the pot when brewing your coffee. Slow brewing (with a system like the one here: Uno Casa) can also decrease the amount of bitterness in your coffee.

3. Can cause nausea

Excessive amounts of tannins can cause nausea, particularly if you consume tannins on an empty stomach. However, tannins in tea are more likely to cause nausea than tannins in coffee. Furthermore, eating something beforehand, or with your coffee, will also help reduce any risk of nausea.


In conclusion, you can see that tannins bring many benefits with a few drawbacks, which can be avoided in most cases.

Drinking coffee in moderation and choosing a cold-brewed Arabica blend can bring you coffee lower in tannins, which is particularly appropriate if you are a heavy coffee drinker.

However, if coffee is an occasional beverage for you, you can drink various types of coffee as you like without being overly concerned about the tannin content.

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About Shabbir

Shabbir is the Chief Caffeine Officer at Coffee In My Veins. When he's not weighing out coffee beans for his next brew, you can find him writing about his passion: coffee.