Is coffee good for coloring hair?

Fiona’s fear: I use Pantene’s Brunette range of shampoos to maintain my dyed brown hair. This is met with huge scorn by my mother in law who insists that nothing is more effective at maintaining glossy brown hair than rinsing it with an espresso or two once a week. Is coffee an effective way to treat and prolonged coloured hair or is it as useful as the beer rinse (ie- not particularly).

The Left Brain responds:

I love questions like this because the answer can be easily proven by a simple test. But before I explain, let’s talk about products for brunette hair.

Brains on Brunettes

Products like Pantene’s Brunette Expressions and John Frieda’s Brilliant Brunette Luminous Color Glaze work because they contain a high concentration of dyes that stain the hair. These dyes won’t permanently color hair and they can’t lighten your natural hair color, but they can give your shade a boost that will last through several shampoos. There are lots of materials that will stain hair in a similar fashion, including fruit juices and coffee, but they won’t provide as much color as intense dyes.

Colorful chemistry

To find out if coffee will color hair I brewed up a pot of double strength espresso. Then I took a tress of bleached blond European hair. I used bleached hair for two reasons: the bleaching makes the hair more porous so it soaks up more of the coffee and the coffee color will show up better on light blond hair. As you can see from the “before” picture below, the hair is very blond. (This will vary depending on the color reproduction of your computer monitor.)

Then, I soaked the tress in coffee overnight to see how much the color would change. Here’s how the tress looked after soaking in double strength coffee for 12 hours. As you can see, the hair is a little bit darker, but not very much. (There’s a slight color shift due to the camera, but to the naked eye the hair color barely changed). If the effect is this slight on blonde hair, it will be almost impossible to detect on dark hair. So I’m afraid I’ll have to say that your mother-in-law’s assertion is incorrect.

The Beauty Brains bottom line

Based on this quick experiment, I conclude that while coffee can stain hair the effect is too slight to be a practical hair treatment. (I realize that a larger scale test with multiple hair types is required to verify these results, but based on my prior experiences in the lab this color change is pretty typical.) So don’t expect to see a Starbuck’s Shampoo or organic hair color on your local supermarket shelf anytime soon.

What do YOU think? Have you ever used coffee or other homemade hair colors? Leave a comment and share your colorful concerns with the rest of the Beauty Brains community.