What are Tannins?
Tannins are a natural organic material that can be the byproducts of nature's fermentation
process, be created as water passes through peaty soil and decaying vegetation. This can cause water to have a faint yellow to tea-like color, and can cause yellow staining on fabrics, fixtures, china and laundry.
Tannins may give a tangy or tart aftertaste to water. They may also cause water to have a musty or earthy odor. Tannins - also known as fulvic or humic acid - are more common in surface water supplies and shallow wells than in deep wells. Water in marshy, low-lying, or coastal areas is also more susceptible to tannins.
What are the health effects of Tannins?
Tannins are considered an aesthetic problem. While they may make water unappealing to
drink and stain laundry, they present no health hazard.
Should I test my water for Tannins?
Tannins create a light yellow to dark brown discoloration in the water. A simple test for
tannins involves filling a clear glass with water and letting it sit overnight. If the color settles to
the bottom of the glass, the discoloration is most likely caused by iron and/or manganese and
not tannins. If the intensity of the color remains intact, it is most likely caused by tannins. We can test for tannins in our lab at EDS.