Don’t worry, I’m not going to get all Bill Nye on you because BBQ is quite simplistic but there is something magical about how smoke and heat creates such tasty results.
Two of the most prominent aspects of BBQ is the formation of Bark and a Smoke Ring which are what separates real BBQ from anything done in a crockpot. Here is a quick breakdown of the science behind both:
When you first look at this brisket, most people would assume that it has been burnt to a crisp and would be a dried out hunk of meat. Sure that may happen if done on a gas grill at high heat (There is a reason my father earned the nickname “Torch”) but when done over a long period of time at lower heat over coals, the meat is moist and juicy and the outside is like candy.
You see, the bark (or crust) that forms is due to a chemical process between smoke, water (moisture) and the salt that is generally in a dry rub. As your meat of choice slowly cooks, moisture from the meat and water vapor in smoke dissolves the water soluble compounds in the rub, such as the salt and sugar, melting the rub into a gritty slurry. Fats then bubble up from within, mix with the rub and dissolve some of the spices that are fat soluble. Finally, the smoke particles cling to the surface goo and the colour change happens depending on how much wood is used to create the smoke and the length of time the meat is left exposed.
This pic shows how two different barks can form on ribs depending on the length of exposure. Both of these were cooked at the same temperature for the same length of time yet the one on the left was exposed to smoke longer than the one on the right. You may be surprised to know that both have the same tenderness to the meat…only the outside texture is different. So depending on your personal taste and visual preference, you can opt for a slightly darker but saltier/sweeter taste or the traditional mahogany look. Personally, I am a fan of the red mahogany for ribs and dark bark for a brisket.
One thing to always be aware of when smoking meat is that the actual smoke should be a pale blue tint…not a sooty white fireplace kind of smoke. The last thing you want to do is have your food taste like an ashtray and white/grey smoke will do that. As you can see here, the cooker closest to you has hit the “holy grail” while the one behind it is spitting out the nasty stuff. 🙂
Ok, now that that public service announcement is out of the way, lets take a look at what the Smoke Ring is all about:
One of the sure fire ways to tell if meat has been actually smoked is the ridge of pink that forms just below the surface of the bark. Granted, a smoke ring does not impart any flavour but it does provide the authenticity to your product.
Basically the key to a smoke ring is moisture. When BBQ’ing, moist meat holds onto smoke more readily than dry meat. Less smoke sticks as the cooking continues because the surface of the meat begins to dry. For this reason putting a pan of water in a smoker helps create a smoke ring because the evaporating water condenses on the meat. It is also equally important to spritz the meat during the cook to help keep the moisture content up on the surface.
As smoke particles and combustion gases land on the surface of meat, especially cool moist meat from the fridge, they condense, dissolve, and some are moved deeper into the meat by diffusion and absorption. The cells are simply seeking equilibrium. The process is the same as when someone lights a cigar in a room. All the smoke starts out near the cigar, but eventually it spreads throughout the room as it achieves equilibrium. After a while it penetrates clothes, furniture, and even food. Because it is water soluble, cigar smoke will get into wet things first, like your wife’s eyes. Before long you and your cigar will be seeking equilibrium in the garage. 🙂
The result of the smoke entering the meat is that pink ring. The thing to remember is that regardless of cook time, the smoke can only penetrate so deep so you cannot get a smoke ring much thicker than what is pictured…roughly 1/8 – 1/4″. One other takeaway for you is that a smoke ring best develops on a cool, thawed piece of meat…meaning don’t let the meat sit on your counter and get up to room temperature before putting in on the cooker. As soon as you take it out of the fridge, rub it up and throw it on to help achieve that professional looking smoke ring!
Well there you have it. A quick lesson in the science of BBQ. How do you prefer your bark to be? Is there a special rub that you use to help create that crust? Now that you know that moisture is key to a smoke ring, go give it a try on whatever cooking device you prefer…I’d love to hear about your successes.
Happy New Year everyone! 🙂