BBQ enthusiasts have their own preferences as far as charcoal versus gas, butane versus propane, slow smoking versus fast smoking but most will agree that purchasing commercially made charcoal is expensive. A cheap alternative involves making your own charcoal briquettes from scrap materials that no one else wants. You can use scrap wood, agricultural waste like corn stalks and husks or wood from downed trees. It's the same process that is in use in Third World countries where commercially made charcoal is not an option.
Remove the lid from the 50-gallon barrel and inspect the bottom for debris. The barrel should be one that has not been used to transport or store toxic materials. Food-grade barrels for vegetable oil or food oil waste would be ideal. If there is debris, spray the interior with a garden hose to clean it out and remove the debris.
Cut one hole, about 1 1/2 inches in diameter, in the centre of the bottom portion of the steel barrel using the steel snips. Then cut five more holes every few inches around the edge of the barrel in a bicycle spoke pattern.
Stuff some dry ignition material into each of the holes with the barrel resting on its side. Set the barrel vertically onto the bricks. This will allow air flow so the fire can burn.
Fill the barrel with the agricultural waste, wood or other material that is rich in carbon. The material should be roughly the same size so that you don't end up with one piece fully carbonised and the rest unburned. It's best to prepare either all agricultural waste, all wood or all other material as each will have a different amount of time that it must burn to produce carbonised coals.
Light the bottom ignition material and let the barrel smoke for about five to ten minutes. The key in making coal and not a barrel of ashes is to starve the fire of oxygen before the fuel is burnt completely.
Cover the top of the barrel with the lid and carefully remove the bricks underneath the barrel. Let it smoulder for an hour for agricultural waste or four to five hours for thicker pieces of wood scraps. Remove the lid and check the coals. If the material snaps and breaks easily, it is ready. If not, repeat the process until it does snap and break easily.
Crush the carbonised material into dust and add your blend of 2 cups cornflour, 2 cups sawdust and 1 cup water for each half pound of carbonised material until the result is a thick sludge. This will act as a binder to hold the dust together in the form of a briquette. The blend ratios will depend on what kind of material has been carbonised and may take some experimentation to perfect.
Punch a small hole into the bottom of each of the muffin cups, these will be your moulds. Scoop a handful of the sludge into the moulds. Press the sludge into the mould or tap it a few times with a hammer and a flat round press roughly the same size as each muffin cup.
Tap the briquettes out of the tins and set them aside to dry for one week. You are now ready to use your DIY briquettes.