It was a fairly simple process - first collect some wood just a bit thicker than your thumb, they decided that we would try different types of wood like green ash and dried ash, green and dry hazel, holly etc. Once collected they needed to strip the bark off (apparently this makes better drawing charcoal - they also noticed the green twigs were easier to peal) cut into lengths and place into a tin.
These were then placed on the fire until steam stopped coming out of the holes.
Some of the first efforts were underdone so the tins went back on the fire.
The finished article was tested, then safely bagged up for next months lesson :)
Just a note - some of the tins appeared to catch fire but still produced great charcoal.