Tannin facts for kids

Tannins are special chemical compounds that taste a bit bitter. They can connect with proteins, which are important building blocks in living things. You might have tasted tannins in some drinks or foods!

You can find tannins naturally in many things, like:

• Wine
• Tea
• Some fruits, like grapes, apples, and pomegranates
• Tree bark, especially from oak trees

Tannins are also very useful for making leather. They help treat animal skins to make them strong and last a long time. While natural tannins from trees are used, people often use man-made (synthetic) tannins for this purpose today.

What Are Tannins?

Tannins are a type of polyphenol, which is a group of plant-based chemicals. They are known for their ability to bind with proteins and other large molecules. This binding is what gives them their unique properties, like their bitter taste and their use in making leather.

How Do Tannins Taste?

When you drink tea or wine, you might notice a dry, puckering feeling in your mouth. This is often caused by tannins! They react with the proteins in your saliva, making your mouth feel less slippery. This feeling is called "astringency."

Where Do Tannins Come From?

Plants make tannins as a natural defense. These compounds can make plants taste bad to animals or insects, protecting the plant from being eaten. Tannins are found in different parts of plants, including:

• Leaves (like in tea plants)
• Bark (like in oak trees)
• Fruits (like in unripe bananas or persimmons)
• Seeds (like in cocoa beans)

Uses of Tannins

Tannins have been used by humans for thousands of years for various purposes.

Tannins in Food and Drinks

Tannins are a natural part of many foods and drinks we enjoy.

• Tea: The color and some of the flavor of black tea come from tannins.
• Wine: Tannins from grape skins, seeds, and oak barrels give red wine its structure and help it age well.
• Fruits: Unripe fruits often have more tannins, which is why they can taste very bitter or astringent. As fruits ripen, the tannin levels often decrease.

Tannins in Leather Making

One of the oldest and most important uses of tannins is in the process of making leather, called "tanning."

• Traditional Tanning: Historically, people used bark from oak, chestnut, or mimosa trees, which are rich in natural tannins.
• How it Works: The tannins react with the proteins in animal hides (skins). This process changes the hide, making it more flexible, durable, and resistant to decay.
• Modern Tanning: Today, synthetic tannins are often used because they are more consistent and faster to work with.

Images for kids

• 

  A bottle of tannic acid solution in water

• 

  Strawberries in a bowl

• 

  Tannin in a plastic container

• 

  Tannin-rich fresh water draining into Cox Bight from Freney Lagoon, Southwest Conservation Area, Tasmania, Australia

• 

  Bog-wood (similar to, but not, driftwood) in an aquarium, turning the water a tea-like brown

• 

  Upper Tahquamenon falls Panoramic view

See also

In Spanish: Tanino para niños