Why Does Wood Turn Black? (The Fascinating Chemistry Of Wood)

why does wood turn black

Wood is a very durable material, but it does not stay that way forever.

Do you want to know why does wood turn black? Wood that is exposed to sunlight over an extended period of time will darken and even turn gray. This weathering occurs because the sun causes chemical changes to the tannins in the wood, kind of like oxidation.

The thing about this process is that there are many steps involved why it does not happen as quickly on some types of wood as others.

In order to have your own piece of beautiful furniture last for years without turning color, you should know how to protect or manipulate wood colors!

What Is Black Wood?

The term black wood is typically used to describe furniture that has been stained or painted a dark color. This is why many people mistake the sun (which can cause wood to turn black) as being what turns the paint on their piece of furniture black, but this process can also happen because it’s in contact with certain substances such as dust and dirt.

What Does It Mean When Wood Turns Black?

Why Does Wood Turn Black

Wood turns black when it is exposed to UV rays due to a chemical process called oxidation. This means that the wood will turn dark brown over time, or even gray if left out for too long

The color of your furniture may also be affected because different types of woods have differing levels of tannins which can make them more resistant to this process.

The weathering process also occurs because light creates a chemical reaction in the tannins of the wood. That then cause it to darken over time. It is thought that this natural aging process has been used for centuries by furniture makers and artisans who wanted their creations to be more beautiful with time.

Wood can also get black in contact with water and other substances, such as dirt or grease. Sometimes the black color indicates mold or bacteria.

How Can I Stop My Wood From Turning Black Or Get It Back To Its Original Color?

There are several different ways to keep wood from turning black, but they all involve some form of protection. There is a sealant you can put on the furniture. That will protect it and prevent it from getting black. As well as other methods such as using linseed oil or wax.

The most common way to get your furniture back to its original color is to sand it down and re-varnish or paint the surface.

When the surface of the wood is black, there may be mold present. Another possibility is that tannins in the wood reacted with minerals in the water. To fix both problems, start by removing any existing finish and then bleaching or replacing the wood.

You can read more about woodturning and wood in general on our blog.


Wood is a very durable material. But it doesn’t stay that way forever and will eventually weather over time with exposure to the sun’s ultraviolet rays. The chemical process called oxidation can cause your wooden furniture or structures to change colors as well.

If you want to keep your wood looking the way it did when you first installed it, invest in a good quality finish. That will protect the natural color of the wood. 

Thank you for reading our article!