Charcoal or propane: Which makes food taste best on the barbecue?

ROB MIFSUD

When I bought my Big Green Egg, I thought all my grilling problems were solved. It is the Cadillac of barbecues, after all: My 99-kilogram ceramic hulk bends heat to its will, morphing into a 500-degree blast furnace that takes a steak to a juicy medium-rare in minutes, or a gentle 90-degree slow cooker that transforms pork shoulders into barbecued succulence over the course of 24 hours.

Then I went to buy charcoal. How hard could that be? Well, at the “charcoal showroom” at Ontario Gas Barbecue, in Vaughan, Ont., not only did I have to choose among more than a dozen brands of hardwood lump charcoal, but I also faced the option of wood chips, wood pellets, and a dizzying myriad of other ways to coax the best from my backyard beast. Jamaican pimento, anyone? Charcoal reviewing websites (yes, that’s a thing) such as nakedwhiz.com made it easier to choose a good charcoal, but I still wasn’t clear what “good” charcoal even is.

So I tracked down the experts to find out how they use everything from propane to post oak (popular in Texas barbecue) to make great food. Just as in every other corner of the food world, there really are carbon-based lifeforms who fuss over carbon-based fuels – their temperature, ash content and flavour profile – the way others fuss over Bordeaux and single-plantation chocolate. Their hard-won knowledge can make us all better weekend warriors.

It doesn’t get any simpler than burning wood, and in the world of southern barbecue there are still a few stubborn souls, like Flint and Randy McLay of McLay Brothers BBQ in Thamesford, Ont., for whom charcoal of any kind is much too refined. The brothers specialize in cooking whole hogs for catered events, and the only fuel they believe is up to low, slow job of cooking a pig are logs of cherry wood. Without wood “you don’t have the flavour and you don’t have the colour,” says Flint.

Using fruit and nut woods that have been seasoned for 12 months to 18 months to eliminate tannins and other acrid flavours is as authentic as southern barbecue gets, but it’s a dying tradition (its adherents are knows as “stick burners” within their own community). A whole 120-pound hog takes about 20 hours and 135 kg of wood to cook, “and we typically have to put wood in about every 45 minutes, so we don’t get much sleep,” Flint says.

Because of health and safety regulations, in addition to consistency problems, seasoned hardwood translates particularly poorly to the restaurant environment, but there are a few holdouts. At Barque Smokehouse in Toronto, owner David Neinstein adopted a compromise solution. His two smokers use natural gas to ignite and supplement the raw hickory, cherry and sugar maple he uses. If the wood runs out (having an employee stay overnight isn’t practical) or doesn’t burn hot enough, the gas kicks in.

If hardwood is as basic as it gets, and the propane, hardwood lump and briquettes that fuel most of our backyard rigs inhabit the popular middle ground, then the sophisticated outlier is surely binchotan, Japan’s traditional charcoal.

The most exclusive binchotan is produced from the ubame oak trees of Wakayama prefecture, and comes in rods that ping when struck together. At $100 for 10 kg, quality binchotan can cost more than the food it cooks, but adherents insist on this activated charcoal which they say offers a longer, hotter, more consistent burn and less smoke.

At Kaiseki Yu-zen Hashimoto in Toronto, executive chef and owner Masaki Hashimoto uses Japanese binchotan charcoal to make dazzling creations such as Hoba Yaki, grilled wagyu striploin served on a pool of miso sauce swirled atop a hoba leaf. That is, of course, when he is lucky enough to find binchotan he can import from Japan.

Executive sushi chef Kazuhiro Hayashi, of sister restaurants Miku and Minami in Vancouver, cooks with this charcoal in a novel way. His chefs run a blow torch over rods of binchotan perched just above alternating layers of rice and fish coated with a squeeze of secret sauce to add “a little hint of smoke” to signature aburi, or “flame seared” sushi.

Are these people blowing smoke? Probably not, according to Chris Young, chief executive officer of culinary education website chefsteps.com and co-author of the epic Modernist Cuisine cookbook, the obsessively researched bible of cooking science.

But you and I probably are. Whether you grill with binchotan, briquettes or propane, you are cooking with carbon. Flavourless carbon, that is. In and of itself, carbon adds no flavour to food. Now here’s the but: Your choice of fuel can still lead to the subtle aromatic distinctions that leave most of us convinced that food cooked over charcoal tastes superior to food cooked over propane.

To understand why, we need to delve into the science of charcoal and grilling. Young’s research led him to conclude that the grilled flavour we know and love is actually the product of what he describes as a “gaseous marinade” that bathes food when drippings from items on the grill strike the heat source beneath, evaporate, then return to the morsels above as a delicious coating of volatile compounds. The catch is that the set of flavours generated by this reaction varies depending on the temperature.

“What most people don’t realize with charcoal is that you’re mostly cooking with the glow of the coal, not the hot air coming off it,” says Young.

The main difference between hardwood lump, briquettes and binchotan is ash content, which is commonly used as cheap filler in mass-market commercial briquettes. All of these charcoals burn at a temperature between 1,200 and 1,300 degrees , but that thin film of ash makes all the difference.

“Ash doesn’t really turn down the temperature – it’s more like a shade over the light bulb that dims how much radiant light is hitting the surface of the food,” Young explains. “So purists tend to say that hardwood charcoal tends to sear really fast, and that’s true, but not because it burns any hotter; it burns with less ash, so it burns brighter.”

As for the so-called stick burners, they almost certainly are on to something. Carbon is carbon, true, but wood is not carbon. If you have ever been camping and found yourself beguiled by the taste of a freshly caught fish grilled over the campfire, chances are it wasn’t just the freshness of the fish. As seasoned hardwood makes the journey from log to lump of carbon in a fire, the smoke imparts mouthwatering notes to everything from a wiener to a s’more.

There are lessons we can take from this: If you use charcoal, it’s not worth sweating over which brand you choose unless you’re after a really great sear, in which case you’re probably better off springing for a lower-ash product. You can benefit from the enhanced flavours of wood, however, by either sprinkling a handful of chips over hot coals or by wrapping them in tinfoil before using them on a gas grill. Armed with a little knowledge, we can all savour victory as weekend warriors.

Chris Young’s grilling tips

Never soak wood chips: “When you soak wood, everyone says, ‘Oh, you get more smoke.’ What you’re actually seeing is the fog of water. But it’s worse than that. When wood smoulders at a low temperature because it was wet, you greatly increase the amount of carcinogen you produce. By not soaking your wood chips, you get more of a group of molecules, called phenolics, that create the flavour of smoked foods.”

Grill shape matters: “If you want a grill that cooks evenly at the edges and the centre, the round shape is about the worst shape you can have – the angles are all wrong. It is light that is mainly cooking your food: A straight-sided grill that’s shiny will essentially make the grill cook more evenly. … So if you can find a grill that’s straight-sided and then wrap the sides in foil, it’ll [cook] more evenly.”

Clean the grill: “While it’s still really hot, take some aluminum foil, shiny-side down, and let it bake for about 20 minutes. The reflection ensures that your grilling grate gets to about 800 degrees, and all of that goop will turn to ash that you can just wipe off.”

Don’t rush: “People use accelerants to try to light the grill faster, and you start cooking over petrochemicals. Not delicious. Your gas burner should burn clear and blue; it means the only thing being produced is water and carbon dioxide. If your gas grill is burning with a yellow flame, that means the propane or natural gas is not completely combusting, and it means you’re going to get a lot of leftover propane or natural gas on your food.”