Mastering the Grill_ The Owner's Manual for Outdoor Cooking - Andrew Schloss [14]
FUELS
PROPANE. The most popular grills in America are fueled by propane. Propane and natural gas are similar but different fuels. The hoses on a gas grill will tell you which fuel the grill uses, because propane hoses are about half the diameter of natural gas hoses. Why? Because propane gas has the ability to be compressed into a liquid, reducing its volume and making it suitable for storage in a portable tank. Propane, properly termed LP gas or liquid petroleum gas, comes from the refining of crude oil and natural gas. Liquid petroleum gas is composed of 90 to 95 percent propane and smaller amounts of propylene, butane, and butylene. It’s colorless and odorless, but ethyl mercaptan is added so you can smell it easily for safety purposes. Inside the container, LP gas is in two states of matter: liquid and vapor. The liquid falls to the bottom and the vapor remains on top. Most propane tanks are filled to about 80 percent capacity, leaving about 20 percent for the vapor to expand during ambient temperature fluctuations. Propane tanks also come with an overfill protection device, or OPD, to prevent hazardous overfilling of the tank. When you open the gas valve and withdraw pressurized liquid propane from the tank, it reverts from its liquid state back to a gaseous state. Propane (C3H8) has three carbon atoms and eight hydrogen atoms. Unlike solid fuels such as lump charcoal, gaseous fuels like propane emit water vapor when burned, due to their hydrogen atoms, meaning that they don’t burn as hot or as dry as coals.
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A MAKESHIFT FIRE STARTER
Manufactured fire starters come in many forms, from lighter fluid and paraffin cubes to compressed blocks of sawdust (see page 27 for more). But any easily combustible material, such as dry leaves, paper, or a candle, can be used to start a fire. To make a simple fire starter for fireplace fires or campfires, wad up a paper towel and set it in a paper cup. Pour in cooking oil to almost fill the cup. Saturate the paper but leave an inch or so of the tip exposed out of the cooking oil to act as a wick. Put the makeshift candle beneath your fuel (wood or charcoal) and light the wick. The candle will completely burn itself up, igniting the other fuel in the process.
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NATURAL GAS. Another petroleum product, natural gas is similar to liquid propane gas but is composed of 90 to 95 percent methane and smaller amounts of ethane and propane, as well as ethyl mercaptan for odor detection. Methane (CH4) is a natural gas produced by decaying matter. Grills fueled by natural gas are connected directly to the gas line so that you don’t have to bother refilling a small tank, as you do with propane—a convenience that more and more grill aficionados opt for, especially those with outdoor kitchens or grills that remain outside in fair weather year-round.
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CHARCOAL BRIQUETTES. Charcoal comes in two ready-made forms: briquettes and lump charcoal. Briquettes burn steadily and evenly, but some brands are made with cheap scrap wood, sawdust, borax to bind it all together, nitrate and petroleum products to help the briquettes ignite, and lime to whiten the ash so you’ll know when the coals are ready for cooking over. When using briquettes, we find that national brands tend to perform more consistently and produce better flavor than store brands.
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LUMP CHARCOAL. This type of charcoal is closer to real wood in its natural state, and we prefer it. No binders or other additives are used to make lump charcoal. Whole logs are burned and then broken into rough pieces that resemble the charred wood left after a campfire. All charcoal is essentially charred wood made by burning wood with intense heat (about 1,000°F) in the absence of oxygen to drive off the wood’s water, its volatile compounds such as methane and hydrogen, and its tars such as benzo(a)pyrene. What’s left is carbon, trace volatile compounds, and