Re: What is in black walnut hulls that can stain skin for so long?

Hi Kelly,

I spoke with Dr. Mary Ellen Camire, who is a faculty member in our 
Department, concerning your questions. She has alot of expertise with 
natrually occurring chemicals. She said that tannins are the compounds found 
in black walnut hulls that stain the skin. The reason they lose the ability 
to stain the skin when they age is that moisture is lost from the hulls. 
The tannins are then bound to the solids of the hulls. If you were to 
extract the ground up hulls with alcohol or a mixture of alcohol and water, 
you should be able to extract the tannins. By evaporating the solvents, you 
can concentrate the tannins. We were glad to see a question from Maine 
since we are in the Department of Food Science & Human Nutrition at the 
University of Maine.

Al Bushway
Profeesor of Food Science