In the 18th century, black powder was manufactured in specialized powder mills rather than simply mixing ingredients by hand. It consisted of three materials: **saltpeter (potassium nitrate), charcoal, and sulfur**.
The process generally involved:
1. **Purifying the ingredients**
Saltpeter was refined by dissolving and recrystallizing it. Sulfur was purified, and charcoal—often made from soft woods such as willow or alder—was produced under controlled, low-oxygen conditions.
2. **Grinding ingredients separately**
Each material was reduced to a fine powder. They were usually processed separately at first because the combined mixture was highly sensitive to sparks, friction, and heat.
3. **Incorporating the mixture**
The ingredients were blended while damp, often in heavy wooden or stone-wheeled incorporating mills. Water reduced dust and accidental ignition and helped produce a more uniform mass.
4. **Pressing and “corning”**
The damp powder mass was compressed into hard cakes. These cakes were then broken up and passed through sieves to create grains of different sizes. This “corned” powder burned more consistently and powerfully than loose, finely mixed powder.
5. **Glazing and drying**
Grains were tumbled to smooth their edges and reduce dust, sometimes with a small amount of graphite late in the period. They were then carefully dried and graded by grain size for muskets, cannon, blasting, or priming.
6. **Testing and packing**
Manufacturers tested batches for strength and consistency, then packed the powder in wooden barrels or other containers designed to minimize moisture and sparks.
Powder mills were deliberately built as **small, separated buildings**, often beside streams that powered the machinery. Lightweight roofs, earthen barriers, non-sparking tools, and strict separation of production stages limited the damage from frequent accidental explosions. Major military powers increasingly regulated and centralized the industry during the 18th century because powder quality had a direct effect on artillery range, firearm reliability, and battlefield logistics.