Why does wood become darker when it ages?

Question

I have lots of pieces of pine furniture which have different colours depending on how old they are. So, I just wondered why that is. I guess it has something to do with structures and chemical compounds that were already in the wood when it was still alive, so I hope this is not off-topic here. What processes take place in dead wood when it ages? What determines the colour it will have? For example, pine and spruce wood looks very similar when freshly cut, but will develop very distinct colours afterwards. Is there also wood that does not become darker? Is it something to do with the processing of wood, or will that happen to any stick you leave lying around in your room (so it doesn't rot)?

Answer 1

Hi! I'm Shirley! Good Question! Lots of factors can affect the changes in the appearance of wood, whether it's furniture, an art sculpture, etc. I don't see any mention of what type of furniture finish added to your pine furniture mentioned here. That could be a factor, too. However, there are various possibilities.

You probably know that wood contains natural oils and chemicals. Oxidation--exposure to oxygen can cause a reaction affecting the wood in your furniture's appearance. Sometimes you can tell or guess how old your furniture could be, as it ages, compared to other pieces like it.

Is your furniture near light--Sunlight or any type of ultraviolet light? The process is similar to when our skins tan/get darker.

Do you live in the city or country? How fresh is your air? Is your air usually humid? Climate-Controlled? Chemical changes have an effect on the tannins in your wood furniture.

If your furniture is antique, or outdoor furniture, depending on how it was or is cared for, has it ever had exposure to mold or insects--even when it was lumber, before it was created into furniture? One can still have a beautiful piece of furniture with past biological influence. I happen to think that for whatever reasons your furniture has darkened, it can have a charming appearance, and make for great conversation.

I hope that these comments help answer the possibilities of your furniture's appearance for you. Years ago, I used to sell furniture, for one of my various jobs and had always admired the special characteristics of wood furniture. Thanks for asking!