Items you will need
Hardwood chunks (5-by-5 inches, 50-to-55 lb.)
Wood and kindling
55-gallon steel drum with lid
16-gallon steel drum with lid
2 1/2-inch square metal rods
Small steel bar
Sand or dirt
4 fire-treated bricks
Lighting fluid (optional)
Lump charcoal burns hotter and cleaner than standard briquettes, which are often made with charcoal dust, sawdust and other binders and chemicals. Making your own charcoal is also handy if you have an excess of hardwood you need to get rid of. There are two methods: The indirect produces less smoke and pollutants, requires less skill and produces high-quality charcoal, but is more time-consuming to set up. The direct method is easier to set up and to identify the end point, but also requires more skill to control the burning, and the end point includes the burning of the new charcoal.
Cut a 12-by-10 inch square hole on the side of the 55-gallon steel drum at the bottom. Cut or burn four holes, two on each side of the drum, about 8-inches up from the bottom--large enough to fit the 1/2-inch square rods. Thread the rods through the holes.
Cut six holes, about 3/8 inches each, into the bottom of the 16-gallon steel drum to allow gases to escape. This drum is called the “retort.” Fill the retort with the chunks of hard wood and place the lid on top.
Place wood and kindling in the 12-by-10 inch hole of the 55-gallon drum and start the fire. Place the retort inside the drum, resting it on the rods.
Wait for the fire to get really hot and place the lid for the 55-gallon drum on top, propping it open slightly with the small steel bar.
Keep an eye on the smoke. You should be burning for about three hours and the smoke should be white, which means that the water, tar and other compounds in the hardwood chunks are being released. Keep the temperature up by occasionally adding wood to fire.
Watch for the smoke to stop, which means the gases have been burned out. Pull the rods out to drop the retort into the burned wood and ashes, stopping the flow of air to the charcoal inside.
Wait an hour, then lift the retort out of the 55-gallon drum. Wear welder’s gloves, as the retort may not be cool enough to handle. Place the retort in dirt and allow it to cool further.
After about two more hours, check to see if the retort is cool enough to touch. If so, remove the lid to check the results of your burn. If successful, the hardwood chunks inside should have reduced by about a third, and been converted to lump charcoal.
Cut or burn five 2-inch holes in the bottom of the 55-gallon drum. Set the drum atop the four bricks.
Place kindling and newspaper at the bottom of the drum. Place the chunks of hardwood in the barrel. Light the fire from the bottom of the drum.
Wait for the fire to burn hot, then use a shovel to move dirt or sand underneath the drum, leaving about a 4-inch gap between the top of the dirt pile and the bottom of the drum. This will restrict airflow. Lid the drum, using the small steel bar to slightly prop it open.
Keep an eye on the smoke. It should be white, meaning that the water, tar and other compounds are burning out of the wood. The burning should last for about three hours. If you see the smoke begin to slow, bang on the drum to settle the wood. This should help produce more smoke.
Watch for blue smoke after about three hours. This means that the wood has become charcoal and is starting to burn. Cut off the airflow to the fire by piling more dirt around the base of the drum. Remove the steel bar from the top and secure the lid. Let it cool for 18 to 25 hours, then dump the charcoal from the drum to pack away or use.
If you can’t get new, clean steel drums, make sure you clean them out by burning them to remove any gasoline, oils or other chemicals they may have contained.
You may make a few attempts at first, using either method, before you get the quality of charcoal you desire. Be patient and be safe.