Lump charcoal: Sometimes called charwood or natural lump charcoal, this is the original charcoal, made by burning trees or logs in a kiln, sealed cave, or even underground. Unlike briquettes, lump charcoal is pure wood—free of binders or petroleum-based accelerants. Lump charcoal burns hot, cleanly, and pure. You can refuel a lump charcoal fire with unlit charcoal without producing the acrid smoke associated with freshly lit briquettes. However, natural lump charcoal burns unevenly, hotter at the beginning, cooler at the end, and it burns out more quickly than charcoal briquettes. When you grill with lump charcoal you’ll need to refuel the grill more often than with briquettes, usually after 30 to 40 minutes.
Charcoal briquettes: These are designed to burn evenly and maintain a steady “broiling” temperature of at least 600 degrees F for 1 hour. Traditional briquettes contain wood scraps, sawdust, coal dust, borax, and petroleum binders, so it’s not surprising that they emit an acrid-tasting smoke when first lit. Instant-light charcoal consists of briquettes saturated with lighter fluid. The acrid smoke disappears once the charcoal glows orange and begins to ash over, but you’re still grilling over borax, coal dust, and petroleum binders. And, although the petroleum-based accelerants of instant-light charcoal burn off in theory, they can produce an oily taste when less than completely lit. “Natural” briquettes, which contain only wood scraps and starch binders, are meant to eliminate these problems.