There is charcoal and there is charcoal
We recommend to use high quality lump charcoal. This is quite different from the regular charcoal you pick up in your grocery store. The chunks will be bigger, sparks less and a give a more steady cooking temperature.
Briquettes are made from charcoal powder compressed with corn starch making them very dense. If you use briquettes the lighting time might be a bit longer than regular charcoal. The corn starch will also emit smoke when ignited. There are different types of briquettes offering a selection of density. The harder compressed - the longer burn time.
In order to lower your environmental impact and avoid supporting companies engaged in deforestation we highly recommend everyone to use high quality charcoal from sustainable sources, such as coppiced trees in managed woodland and forests.