How to Make Black Powder | Sciencing
Separate your ingredients. The recipe for black powder is 75 percent potassium nitrate, 15 percent charcoal and 10 percent sulfur. This is usually measured by weight: 75 parts to 15 parts to 10 parts. Finely grind the ingredients. For safety's sake, grind them all separately and clean out the mortar and pestle thoroughly between crushings.