May is National Barbecue Month, and what better way to kick off the celebrations than an in-depth exploration of charcoal, its different forms, and how it got that way? But wait, I hear you say, charcoal is charcoal is charcoal, isn’t it? It’s actually a bit more complicated than that. Here, then, is an overview of the two most common kinds of charcoal, and the difference between them.
The charcoal briquettes you get at the grocery store are actually compressed chunks of ground charcoal and sawdust, as well as non-wood products such as coal dust, limestone, starch, borax, and sodium nitrate (not exactly what we want in our food!). The advantage charcoal briquettes have is their even size and density, which allows for a more predictable burn rate in less expensive grills. The disadvantage of briquettes is that they produce far more ash than lump charcoal, and this ash can choke the fire, limiting the heat output. With a small charcoal grill, this may not be a problem, but the volume of ash produced means that briquettes won’t work in ceramic smokers like the Primo or Kamado Joe. They also cannot be easily used for more than one cooking session. Additionally, briquettes have no flavor of their own, and so impart no flavor profile of their own to the food cooked over them.
Lump charcoal, on the other hand, is made from hardwood which is burned slowly in a low-oxygen environment over a period of several days, through a process known as pyrolysis. (Readers may remember from our chimney safety post that pyrolysis can occur when clearances to combustibles are not met for wood stoves or fireplaces, or when venting materials aren’t connected right; essentially, this means that an improperly-installed wood stove can gradually turn your wall studs into charcoal! Pyrolysis: bad for houses, good for cooking.) This low-oxygen environment is created when wood is either placed into an oven/kiln, or covered with earth and straw, then closed off and left to burn slowly and steadily until the wood is fully oxidized and hardened. The hard wood chunks are then broken down into lump charcoal, which is filtered to remove crumbs and dust.
Because it has no fillers or binders, lump charcoal produces less ash than briquettes, burns hotter, and heats about 20 minutes longer per pound of fuel. Here at Wooden Sun, we use 100% hardwood charcoal in our grills and ceramic smokers, and feel that for flavor, lump charcoal really can’t be beat. We also like to cut the air off after cooking, let the fire die out, and use the remaining charcoal for the next grilling session, which is very difficult to do with charcoal briquettes. A bag of good lump charcoal should have very little dust (there’s always some that settles in the bottom during shipping, but more than a little indicates that your charcoal supplier hasn’t adequately filtered their product before packaging), and only a few small chips.
Whichever form of charcoal you choose for your outdoor cooking, steer clear of lighter fluid. It can impart a nasty chemical flavor to your food, as well as being environmentally unfriendly. There are a variety of fire starters available out there (usually made with some combination of paraffin and compressed sawdust), and products like the Looft Lighter and BBQ Dragon will keep hot air moving over your charcoal to get it up to temperature faster.
-P.S. The links below aren’t actually relevant to your choice of cooking fuel, but your blogger encountered them in the course of her research, and found them too interesting not to share: