Also it is hellaciously difficlult to get the hulls off of green picked nuts, and you will bruise the hulls doing it thus "damaging" them and they will then turn black. I have been picking walnuts all my life, I grew up on a tree farm. Brickey is right that balck walnut hulls stain really badly. If you want to dye with it it does not require a mordant. Use an Iron pot to boil it in and you will get a reasonably black dye.
In a message dated 8/8/2004 10:15:24 AM Pacific Daylight Time, mdud...@king-cart.com writes:

Huh? With the good stuff in the hull, why not just soak the hulls. It allows you to put many more hulls in a given size container, and in any given amount of PGA or Vodka

If you do decide to peel off the green hulls, you may consider wearing gloves as it does stain really badly. It also takes more than the usual time for the stains to fade, if I recall correctly. If any juice gets on any clothing, the stain will be pronounced and permanent. pj

Also, one fifth of Vodka Black Walnut tincture lasts me a couple years. I have no need to make even more. I don't want to keep it too long as it might loose its strength. Every now and then I take two teaspoons on an empty stomach to keep my bug population low. Damaged hulls turn black pretty quick, that is why I said to pick them from the tree instead of picking up dropped nuts. They would be black within 72 hours.

That's true too. I would've pciked them off the tree if I had a ladder tall enough. My tincture is black, and turned that way within 48 hours.

Sharon
The dropped nuts all have black hulls. People were advertising Green black walnut tincture. The walnuts have to be picked for the tincture to have the green tint. They seemed to downrate a black tincture as not quite as potent.

Brickey