Where Does Liquid Smoke come from and How is Liquid Smoke Flavoring Made?

While its name may be a bit nutty, liquid smoke is a legitimate and useful product. It adds a smoky flavor to foods without our having to go out and chop wood and build a fire and do all the rest of it.

Smoking is one of several ancient methods of curing or preserving foods, primarily meats and fish, by killing pathogenic microorganisms. Other long-used methods are drying (think jerky), salting (think bacalao or salt cod), and pickling (think … well, pickles).

Drying works because bacteria can’t grow without moisture, salting works because the salt draws water out of the bacteria’s cells and dehydrates them, and pickling works because bacteria can’t thrive in acidic environments such as vinegar. Smoking works because the smoke contains many bactericidal chemicals. Our ancestors discovered these methods empirically, of course, long before there was any knowledge of pathogenic microorganisms.

Wood smoke can be lethal not only to bacteria but, as all firefighters know, to humans as well, if there is enough of it. When we’re exposed to only a little bit of it, however, we love its aroma (think fireplace on a winter’s night) and its flavor (think smoked trout). But smoke is a mixture of hot gases and microscopic suspended particles, which are more difficult than a genie to capture and put into a bottle. So the food industry invented liquid smoke and not only uses it in prepared foods but bottles it and sells it for home use. You may be able to find liquid smoke in 4 -ounce bottles under the brand name Colgin, in pecan, mesquite, hickory, and applewood flavors.

In a traditional smokehouse, meat is hung from the ceiling, and smoke from an outside fire of moist sawdust is blown in through ducts. In modern commercial smoking plants, the density of smoke, the temperature, and the humidity are all carefully controlled to produce specific effects.

Today, commercial smoking is done in either of two ways: cold smoking, in which the food isn’t allowed to exceed 90 to 100°F (32 to 38°C), and hot smoking, in which the food can reach 200°F (93°C) or higher, and be partially cooked. Some processed meats are hot-smoked and are therefore considered to be cooked (bologna), while others are cold-smoked and sold raw (bacon). Smoked hams may or may not require further cooking; the labels will tell you.

Sausages are a real challenge to classify. The ground meat may be fresh or cured (with nitrites, for example); the filled casings may then be cooked or not, smoked or not, dried or not, and/or fermented or not. In a belt-and-suspenders precaution against bacterial contamination, frankfurters are usually cured, cooked, and smoked, while Italian salami is usually cured, fermented, and then dried. Fresh (uncooked) pork sausage, on the other hand, is neither cured nor smoked.

Vegetables can also be smoked, with mouth-watering results. In the village of La Vera in the Extremadura region of western Spain. I watched bright red Capsicurn annuurn (chili) peppers being simultaneously dried and smoked in long, low, two-level bungalows. The peppers were piled on wooden-slat platforms several feet above smoldering oak logs on the concrete floor below. The dried and smoked peppers were then ground to a velvety brick-red, paprika-like powder called pimenton , which has a smoky, sultry flavor. They make it in two varieties, picante (“sharp” or hot) and dulce (“sweet” or mild), depending on the “heat” of the pepper crop.

(A historical note: Although the New World’s capsicum peppers found favor here and there in Europe after Columbus brought them back, it was the Hungarians who picked up the ball and ran with it. Still renowned today for their use of paprika, they reputedly adopted it when King Carlos V of Spain sent some pimenton  to his sister, Queen Mary of Hungary, who thought it was great stuff and spread the word. Hungarian paprika doesn’t have the rich, musky flavor of pimenton , however, because its peppers are dried without smoke.)

Inevitably, much of a commercial smokehouse’s smoke eventually finds its way up the stack to pollute the atmosphere. And in today’s environmentally conscious society, where there’s smoke there’s fire. Liquid smoke to the rescue!

To make it, one first generates real smoke by burning moist hardwood chips or sawdust. The moisture partially deprives the fire of oxygen to ensure maximum smokiness. The smoke is then blown at chilled condensers, where many of its chemical components (hundreds of different chemicals have been identified in wood smoke) condense to a brown liquid, which is then purified to remove undesirable, and toxic, components. What remains is usually mixed into acetic acid (vinegar) and can be added in that form to your barbecue sauce.

The FDA doesn’t permit a food to be labeled “smoked” unless it has been exposed directly to real smoke from burning wood. Read the label on the package of your favorite hot dogs; some are only “smoke flavored” by having been sprayed with or dipped in liquid smoke.

Now, you have undoubtedly been unable to forget what I said earlier about smoke’s having toxic components. and you’re wondering whether liquid-smoke-flavored foods are safe. Well, what should I say?

Nightmare scenario: I say they’re safe. You eat some and get a headache. An opportunistic lawyer tells you, “You have a case.” He sues me and the food company, stuffs a jury box with migraine sufferers, and wins a $2 million settlement from the company plus $50o from my threadbare writer’s pockets. He takes $1.5 million for himself and runs off after another ambulance, while after paying court costs you’re left with the price of a bottle of aspirin.

So should I say that smoked foods are safe? Okay, I’ll take the plunge.

Yes, the smoke chemicals in purified liquid smoke are safe in the small amounts you’ll encounter in smoke-flavored foods. So sayeth the FDA. Sue them.

Real, gaseous smoke, however, can be quite another story. The decomposition of wood (and tobacco and grilled steaks and hamburgers) by intense heat, a process called pyrolysis, can produce highly carcinogenic 3,4 -benzopyrene and other so-called polycyclic aromatics (PCA’s). But none of these chemicals has been found in commercial, purified liquid-smoke products.

On the other hand. liquid smoke, like its gaseous parent, contains bactericidal and antioxidant chemicals, such as formic acid and phenolics, that may even make a positive contribution to your health.