Black Walnut is a now rather rare nut tree native to the eastern part of North America. It's also known as Juglans Nigra. It used to be a common nut tree until European settlers started to cut it down for it's amazing hardwood. The wood is almost white on the outside (towards the bark) and dark brown on the inside. This makes for beautiful lines and patterns. The wood was in high demand for wooden floors and furniture. The tree became unfortunately almost extinct.
The Black Walnut tree has a defense system to protect it from bacteria and fungal infections. This defense system consists of a mixture of different chemicals that the tree uses for it's protection. It has an amazing "Black Walnut smell". It's hard to describe and unlike anything else but it's a pleasant smell.
The tree uses these chemicals to protect the young leaves and not yet ripe nuts. Only the soft leaf in early spring has this smell and it goes away as the leaves become mature and hard. The green nut hulls (the soft outer part that protects the nut when it falls from the tree) have this smell and the ripe and yellow nut hulls have it to a much lesser degree.
Tincture made from the green nut hulls is an extremely powerful antifungal and antibacterial. Some people call it natural iodine but this is not really describing what this black walnut tincture is. It's not a general purpose oxidizer like iodine. It's a mixture of different chemicals with actions towards fungi and bacteria (probably viruses too). This mixture of chemicals is very sensitive to oxidation. The fresh green hulls are white on the inside but become rather quickly black when exposed to the oxygen of the air. Those chemicals looses their typical black walnut smell as soon as they are oxidized by the air but most of the action against fungi and bacteria remain. I suppose that the fresh and not oxidized sap from these green hulls would be an even more powerful antifungal and antibacterial but it's almost impossible to prevent the oxidation.
We can use the defense system of the Black Walnut tree. Black Walnut tincture is a very effective treatment for fungal infections of the skin such a athlete's foot and ringworm. It can also be used to treat acne-prone skin. Some people use Black Walnut tincture on any mystery skin irritation from insect bites to rashes of unknown cause and it's often an effective remedy. People with nut alergies should not use Black Walnut.
Some people seem to use Black Walnut tincture in combination with Wormwood tincture to treat internal yeast infections and parasites. I have no experience with this mode of use.
Black Walnut tincture is made by harvesting the not yet ripe nuts around mid to and of August. The outer hulls are removed from the nut and put into alcohol. Gloves should be used when cutting the hulls as the fresh sap can stain the skin for several days. The tincture is ready after an infusion time of about 2 to 3 weeks. Some people use dried Black Walnut hull powder to make the tincture but this results in an almost clear solution with rather weak antifungal properties. The dark black Black Walnut tincture made from the fresh green nut hulls is much stronger.
Any unflavored grain alcohol with a ethanol concentration between 40% and 95% can be used to make this tincture. Any alcohol contains some amount of water and fungal infections thrive on humidity but yeast and fungal growth are inhibited by salt water. It is therefore possible to add a bit of table salt to the final tincture. This makes it slightly more effective against fungal infections.
