Tannins | Wise Plate

Q: Are some people sensitive to tannins?

Yes. Some people experience headaches, migraines or stomach pain after consuming tannin-rich foods (such as red wine and dark chocolate). This is sometimes known as the "red wine headache," although the exact cause may be a combination with other substances (such as histamine or sulfites).

Q: How do you reduce the bitterness of tannins in tea?

The secret is controlling the steeping: don't leave the tea bag in the cup forever. Most of the caffeine and flavor come out in the first 2 minutes. The bitter tannins are released more slowly, over time. Use water at the right temperature (80 degrees Celsius, 176°F, for green tea). Boiling water "burns" the leaf and releases tannins immediately. Adding milk binds the tannins and neutralizes the bitterness (but slightly reduces the antioxidants).

Q: Are they safe?

In the reasonable amounts eaten in food — absolutely. The body knows how to handle them, and we benefit from their antioxidant advantages. Problems arise only with very excessive intake, or for people with a particularly sensitive stomach or severe iron deficiency (who should be careful about combining them with meals).

Q: Does cooking fruit reduce tannins?

Yes. Cooking or baking (as in pears poached in wine or quince jam) breaks down some of the tannins and softens the astringent taste. Ripening the fruit (like a banana going from unripe to ripe) also dramatically reduces the amount of active tannins.

Tannins are a diverse group of water-soluble polyphenolic compounds found in abundance in the plant world. Their name comes from the ancient word for processing hides (“tanning”), since in the past tannin-rich extracts (such as those from oak bark) were used to turn animal hides into durable leather that would not rot.

Their role in nature

For the plant, tannins are a defense mechanism. Their bitter taste and the drying sensation they create in the mouth deter insects and animals from eating the leaves, unripe fruit or seeds before they have matured.

The sensory experience: astringency

Tannins are responsible for the familiar “dry mouth” or rough feeling after a sip of heavy red wine, tea left steeping too long, or eating an unripe persimmon.

How does it happen? Tannins bind to proteins in our saliva, make them precipitate and strip away the mouth’s natural lubricating layer. The result is increased friction between the tongue and the palate.

Where are they found?

Tea: mainly in black and green tea (leaves of Camellia sinensis).
Wine: in grape skins and seeds (and also in the wooden barrels in which wine is aged).
Chocolate: in dark cocoa.
Fruit: pomegranate, cranberries, persimmon.
Nuts: in the thin brown skin of walnuts and almonds.

Health benefits and downsides

Like many things in nutrition, tannins are a double-edged sword:

The good: they are very strong antioxidants. They have anti-inflammatory, antibacterial and antiviral properties. Studies point to potential for lowering blood pressure and improving heart health.
The bad: they are known as “anti-nutrients” when it comes to mineral absorption. They bind to plant-based iron and prevent its absorption. In large amounts they may also cause stomach irritation and nausea.

Frequently asked questions about tannins

Question: Are some people sensitive to tannins? Answer: Yes. Some people experience headaches, migraines or stomach pain after consuming tannin-rich foods (such as red wine and dark chocolate). This is sometimes known as the “red wine headache,” although the exact cause may be a combination with other substances (such as histamine or sulfites).

Question: How do you reduce the bitterness of tannins in tea? Answer: The secret is controlling the steeping: don’t leave the tea bag in the cup forever. Most of the caffeine and flavor come out in the first 2 minutes. The bitter tannins are released more slowly, over time. Use water at the right temperature (80 degrees Celsius, 176°F, for green tea). Boiling water “burns” the leaf and releases tannins immediately. Adding milk binds the tannins and neutralizes the bitterness (but slightly reduces the antioxidants).

Question: Are they safe? Answer: In the reasonable amounts eaten in food — absolutely. The body knows how to handle them, and we benefit from their antioxidant advantages. Problems arise only with very excessive intake, or for people with a particularly sensitive stomach or severe iron deficiency (who should be careful about combining them with meals).

Question: Does cooking fruit reduce tannins? Answer: Yes. Cooking or baking (as in pears poached in wine or quince jam) breaks down some of the tannins and softens the astringent taste. Ripening the fruit (like a banana going from unripe to ripe) also dramatically reduces the amount of active tannins.