The color change of Cherry isn’t the only one that has mystified many. Teak, Purpleheart, and Mahogany are some other special cases. We’ll look at how those unique species change color later on, but first we’ll consider exactly what contributes to the kind of extreme color change that Cherry and Teak both display, over time.
Chemical Changes in Wood
The chemical makeup of lumber largely depends on the species and the soil chemistry in which the tree grew. Lignins and extratives are the most significant chemical components, when it comes to color change. Lignins are essentially water-resistant compounds, and they bind the cellulose wood fibers together. Extratives are often extracted from wood in order to contribute to other products, such as pharmaceuticals or Turpentine. While a tree is still living, these chemicals contribute to the color change between sapwood and heartwood.
Once wood has been milled, the same lignins and extractives both impact how wood responds when it comes into contact with the longer wavelengths of light. The light causes those chemical components to break down when they come into contact with heat or with chemicals typically applied to wood. If you sanded an antique table that appears to have a deep cherry finish, you could get a peek at what it looked like when it was freshly milled, hundreds of years ago. At that point, the chemicals would begin to react with light and air, once again, and the darkening process would start afresh.
Special Species Focus: Purpleheart
When Purpleheart is freshly milled, its unique purple hue offers a delightful surprise! However, a not-so-delightful surprise awaits anyone who thinks it will stay that way for long. Purpleheart will naturally change color to appear brown, as its extractives react to its environment.
Special Species Focus: Teak
Unlike Purpleheart, those who desire the honey brown color for which Teak is famous will have to wait a while — though not as long as lovers of Cherry. The same high amounts of extractives (namely, oil and silica) that make Teak ideal for marine applications also cause Teak to appear streaky when it’s first milled. Sometimes it appears to include purples, greens, and grays, but no brown at all.
Special Species Focus: Mahogany
Similar to Cherry, Mahogany begins as a light pink color and turns a deep reddish brown color over time. It never gets quite as dark as that iconic antique Mahogany furniture you’ve seen, though. That will take decades, or even centuries.
The exciting — and sometimes unpredictable — color changes in wood contribute to its natural beauty. While a good sun tan can certainly offer more approximate matching, color-matching wood is certainly not an exact science. Over time, however, it gets better. Like all good things do.
Read the Series
• Wood Color Change, Part 1
• Wood Color Change, Part 2
• Wood Color Change, Part 3