Sitting here, looking out the window, you wouldn’t know that it is spring here in Jersey. Temperatures are more like early March rather than April and the forecast calls for light snow showers. Every weekend I think that I’m going to spend outside planting new bushes and flowers, we get a hard freeze that would not give them the start that they would need, and so the outside chores get pushed back a wee bit longer. The only way that I know it is spring is that my entire schedule is spent carting three kids to and from lacrosse practices, all week long.
Well, that and thinking about the upcoming barbeque season.
As I speak to more and more competitors and backyard warriors, it is clear that the quality and taste of good barbeque starts way before the meat hits the grate. Sure, smoking good meat is about the ability to balance heat and smoke, walking that tight wire between sweet and hot, and finding that perfect temperature in which the bone releases the meat like the fingertips of two lovers on an outbound train, tenderly but with purpose. But the perfect barbeque starts way before this, requiring the same thought, practice, and effort as playing that smoker like a savant. Hard cooks must choose the right fuel, prepare the right rub and sauces, and invest in quality meat before cooking day. They must look to “take the high ground” and recognize that by doing this, the battle can be won before it is even fought. It will save you from having to “fight like the devil until support arrives”. I will be your General John Buford in this first in a series of articles that looks to help you prepare to win the trophy, a finger sucking pop from your neighbor, or a nod from your wife to finally upgrade to that beautiful trailer that you’ve had your eyes on. So grab your notebook, hit the “follow” button on the bottom of the site, and read on. This is New Jersey, and it’s time to put it on the barbeque map.
So why is it that certain types of wood give different flavors to meat? Is this certainly true, or (do I blaspheme?) is it all in our heads, a tribute to the power of suggestion? If true, then choosing the correct wood is integral to preparing an award winning dish and should be given the same amount of consideration as everything else that we do. To answer the question, I traveled back to my alma mater, Cook College at Rutgers University, to speak Dr. Jason Grabosky, professor of Ecology Evolution and Natural Resources, in the hopes that he could shed some light on this and share with us the science behind our favorite choice of fuel. Dr. Grabosky, decked out in a wool hat and carrying a wooden walking stick (which doubled as a teaching tool throughout of discussion), was kind enough to meet with me for some time and answer all of my questions as we walked beneath the trees surrounding Passion Puddle. Much of the information and insights in this post come directly from this conversation, of which I am very grateful. Hopefully, I am able to communicate this conversation well enough and will attest that any mistakes found here (which will be none) are solely mine.
The man, Dr. G!
Trees are almost entirely (90% – 99%) composed of three elements: carbon, hydrogen, and oxygen, laid out certain patterns, in the form of cellulose and lignin. Cellulose and lignin are sugars that are stored by the tree as the product of photosynthesis. Remember from biology class that that photosynthesis uses carbon dioxide from the air and water from the ground and produces glucose (sugar) and oxygen which is then released to the atmosphere. During combustion (or burning) of wood, these huge sugar molecules react with oxygen in the air to form carbon dioxide and water vapor, as well as heat and light (and great barbeque). Because the amount of oxygen in the air is not usually sufficient to combine with all of the carbon in the wood, the combustion is rarely complete, and results in the production of smoke, solid particulates and other waste products that stick to the meat in the smoke chamber and contribute to the flavor. Trees also absorb water, which fills in the cells of the tree, including its leaves, trunk, and roots, so that at any one moment, the tree and its wood will have a variable percentage of water in it, making it more or less difficult to burn and, when it does, influences the amount of water vapor or steam released. So if all trees are made up of the same three elements, how can the various types of trees change the flavor and smell of the meat? Did you catch it? (Suspenseful pause) That’s right, it’s all in the waste products, which consist of creosote and the aromatic compounds in the phenol family such as guaiacol and syringol. Together with the particular oils and other compounds found in nut trees such as hickory and pecan, and fruit trees such as cherry and apple, you can get a multitude of tastes and aromas when smoking your meat.
So how do trees form these compounds, and how can we make sure that we get enough in our wood pile? Creosote and these phenol compounds form in the lignin, not the cellulose. Remember that we said that most of the tree is made up of only three types of atoms: carbon, oxygen, and hydrogen? Well, when a tree wants to create strength and combat gravity, it combines these elements into long, strong chains called cellulose. Most of the trunk and branches are cellulose, allowing it to grow straight and tall, with long reaching branches. But cellulose is not great for compression, or squeezing together, and since certain parts of trees press on one another, and the weight of the tree adds up, it needs another way of arranging these atoms, such as rings. These rings, known as lignin, give the tree more load-bearing capabilities and durability. Lignin is also more resistant to other forms of stress, such as bugs and climatic conditions such as wind. It is more difficult for pests to chew through and contains antiseptic chemicals. Hostile environments can affect the ratio of cellulose to lignin, influencing the taste as much as difference in tree species can. The tree directs a lot of energy and minerals to make sure that these areas are secure, and it is these areas of more complex chemistry that the waste products that we love so much are produced.
Trees also compartmentalize the various functions of the tree, so recognizing the which part of the wood to target for burning is very important. Toward the outside of the tree, lies the sapwood, the “working area” of the tree, where the xylem and phloem transport water and materials up and down the trunk between the leaves and roots. In the center lies the heartwood, a dense area where the tree deposits all its waste from the production of plant matter, via the rays leading from the sapwood. The older the tree, the greater the amount of waste and aromatic compounds that gets deposited in the heartwood, and a more distinguishable difference between the two areas can be seen. When I am smoking up meat for the family, I mostly use apple wood (tyvm Wightman’s Farm, Harding Township). They trim their apple trees often and offer up some of the wood for me to use. But my conversation with Dr. Grabosky has helped me consider my fuel a bit more carefully. To get the optimum amount of desirable aromatics for great tasting meat, I need to target wood with those qualities that hold the most chance of containing the good stuff. Trimmed branched may not contain enough deposited aromatics to give my meat sufficient flavor. As I rifle through the pile of trimmed logs, I’m now going to go right for the heart of the wood, looking for the durability of the lignin or discoloration from accumulated compounds at the center of the trunk.
Choosing the right pieces of wood can be just as important as choosing the right type of wood. While pairing up the species of tree with the right type of meat may be another topic for another time, it is equally important to know your fuel and to choose the pieces that will give you best opportunity to show your barbequing skill. Proper fire box management to get optimum volatilization of these chemicals is also important enough for a discussion all its own. All of these decisions come before the fire is lit, and must be considered to help your meat absorb the taste and aroma that we all associate with quality barbeque. So like the Union army at Gettysburg, look to the high ground to gain the upper hand and ensure victory before the battle has even begun.
Above is a blast from the past for forestry students. Back in the day, students had to know the characteristics of all these types of wood. Most of these blocks had dates on them from the 1920’s and 1930’s. Would have hated to cart this back and forth to class as a teacher. Pretty cool though.