The Ultimate Guide to Tannins in Drinking Water

The Ultimate Guide to Tannins in Drinking Water - Cascadian Water

Gabe Ergler |

When it comes to drinking water, there are many factors to consider. One of these factors is the presence of tannins. But what exactly are tannins and how do they affect the quality of your water? In this blog post, we will explore the world of tannins in drinking water and provide you with the information you need to make informed decisions about your water source.

What are tannins?

Tannins are natural organic compounds that are commonly found in plants, particularly in leaves, bark, and fruits. They are responsible for the astringent taste in certain foods and beverages, such as tea and red wine. In drinking water, tannins can be present due to the leaching of organic matter from decaying vegetation or from the natural geological formations in the area.

How do tannins affect drinking water?

While tannins are generally harmless and do not pose a health risk, they can have some undesirable effects on the quality of your drinking water. One of the most noticeable effects is the discoloration of water. Tannins can give water a yellowish or brownish tint, which can be unappealing to some people.

Furthermore, tannins can also affect the taste and odor of water. Some individuals may find that water with high tannin content has a bitter or earthy taste, similar to that of tea. Additionally, tannins can contribute to a musty or unpleasant odor in water.

How do tannins affect water treatment?

When tannins are present in water, they often form a layer on filtration media, which can become problematic if the media requires contact with the water to function. The accumulation of tannins on the media hinders their ability to perform as designed. In most treatment processes, it is essential to eliminate the tannins for the treatment to operate in a consistent and dependable manner. If tannins are detected in the water, the first step should be their removal, followed by the treatment of other impurities present in the water.

How can you remove tannins from drinking water?

If you are concerned about the presence of tannins in your drinking water, there are several methods you can use to remove or reduce their concentration. One common method is activated carbon filtration. Activated carbon filters are effective in removing some types of tannins, as well as other organic compounds, from water.

Another option is the use of anion ion exchange resins. These resins can selectively remove tannins from water by exchanging them with other ions. This method is particularly useful for water with high tannin content.

Lastly, if you are on a municipal water supply, you can contact your local water treatment facility to inquire about the treatment methods they use to remove tannins. They may employ advanced filtration techniques or other treatment processes to ensure the water meets the required quality standards.


Tannins in drinking water can affect its color, taste, and odor. While they are generally harmless, many people prefer to have clear, odorless, and tasteless water. If you are concerned about the presence of tannins in your water, consider using activated carbon filters, ion exchange resins, or contacting your local water treatment facility for more information. Remember, having access to clean and safe drinking water is essential for your health and well-being.