Just make certain that it is the proper plant, since there are a number of varieties or species. A good herbalist can help. Wash in cold water then bruise the leaves gently and push down into a clean mason jar. Cover with vodka and allow to soak uncovered in a cool dark place for at least two to three weeks stirring occasionally. Strain the tincture into a dark bottle or keep closed in a dark place.
Refrigeration helps soften the bitter taste.
From 10 to 20 drops per day while taking the Black Walnut tincture depending on body weight and tolerance. Many people tolerate capsulated wormwood or an infusion better. Encapsulated can be made by buying gelatin capsules from a pharmacy. Dry the clean leaves and tops then powder them using a small grinder or mano. Pack the capsules and store in a bottle in a cool dry place covered.