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Ec-hasslau.de via Wikimedia Commons // Public Domain
Ec-hasslau.de via Wikimedia Commons // Public Domain

The Next Green Fuel Might Be Growing in Your Yard

Ec-hasslau.de via Wikimedia Commons // Public Domain
Ec-hasslau.de via Wikimedia Commons // Public Domain

Our society has reached a kind of in-between stage in history. We now know that things like plastic containers and fossil fuels are harmful to our bodies and our planet, but we're far from replacing them with the alternatives, and we’re not about to stop buying bottles or driving cars. On the fuel front, at least, we may have made some progress: Scientists say they’ve found a simple, cheap way to get energy out of common lawn grass. They published their findings in the Proceedings of the Royal Society A.

It’s not like we haven’t been trying to come up with other options. Scientists are working hard to find viable ways to turn things like corn, used deep-fryer oil, and algae into energy, but we’re still not there yet.

One of renewable energy’s rising stars is hydrogen, which has a lot to offer as a form of fuel. For one thing, it’s the most abundant element in the universe, appearing in our water, our air, and our plants. It burns efficiently and cleanly without letting off any toxic or greenhouse gases.

The trouble is that while hydrogen may be in lots of things, it can be hard to get it out. Scientists all over the world are attacking the problem from different angles. At the Cardiff Catalysis Institute and Queens University Belfast, chemical engineers began wondering how hard it would be to get the super-fuel out of common plants like lawn grass (which is itself environmentally problematic—one NASA research scientist estimated that our much-watered lawns constitute the largest irrigated crop in the U.S.). 

They used a technique called photocatalysis, which uses sunlight and a chemical catalyst to squeeze hydrogen out of cellulose (a polymer that gives plants their shape and rigidity). The experimental design was relatively simple: The team put samples of cellulose into large flasks and added one of three catalysts—palladium, nickel, or gold—to each. Then they set the flasks under a lamp and measured how much gas each cellulose/catalyst combination produced.

The results were encouraging. All three catalyst-plant combinations responded to the light. The team was glad to see gold and palladium respond, but it was nickel—which is both cheap and abundant—that really got them excited.

To confirm their findings, the researchers repeated the experiment, this time using real lawn grass, which is easier to acquire than pure cellulose. The results held: Lawn grass and nickel really were a good, cheap match.

"This really is a green source of energy,” said co-author Michael Bowker of the Cardiff Catalysis Institute in a press release.

These are, of course, early findings, so don’t start mailing your lawn clippings to the lab just yet. But Bowker is hopeful. "Hydrogen is seen as an important future energy carrier as the world moves from fossil fuels to renewable feedstocks,” he said, “and our research has shown that even garden grass could be a good way of getting hold of it."

Know of something you think we should cover? Email us at tips@mentalfloss.com.

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science
Jan Ingenhousz: The Man Who Discovered Photosynthesis
Public Domain, Wikimedia Commons
Public Domain, Wikimedia Commons

Today, Google is celebrating the 287th birthday of Jan Ingenhousz. While you may not be familiar with the name, you almost certainly learned about his most famous finding in your junior-high science class.

Ingenhousz, a Dutch physician born in 1730, discovered photosynthesis—how plants turn light into energy. In this process, chlorophyll in plant cells absorbs light and uses it to convert atmospheric carbon dioxide and water to sugars, which the plants consume for energy. The cells give off oxygen as a byproduct of the whole cycle.

Previous research by the English chemist Joseph Priestley had revealed that plants produce and absorb oxygen from the atmosphere, and after meeting Priestley in 1771, Ingenhousz conducted further experiments on plants' physiology. He saw that green plants released bubbles of oxygen in the presence of sunlight, but the bubbles stopped when it was dark—at that point, plants began to emit some carbon dioxide. Ingenhousz concluded that light was necessary for these steps to take place. He also found that plants give off far more oxygen than carbon dioxide, thus identifying the benefits of having greenery around to purify the air.

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Food
Brine Time: The Science Behind Salting Your Thanksgiving Turkey
Alison Marras, Unsplash
Alison Marras, Unsplash

At many Thanksgiving tables, the annual roast turkey is just a vehicle for buttery mash and creamy gravy. But for those who prefer their bird be a main course that can stand on its own without accoutrements, brining is an essential prep step—despite the fact that they have to find enough room in their fridges to immerse a 20-pound animal in gallons of salt water for days on end. To legions of brining believers, the resulting moist bird is worth the trouble.

How, exactly, does a salty soak yield juicy meat? And what about all the claims from a contingency of dry brine enthusiasts: Will merely rubbing your bird with salt give better results than a wet plunge? For a look at the science behind each process, we tracked down a couple of experts.

First, it's helpful to know why a cooked turkey might turn out dry to begin with. As David Yanisko, a culinary arts professor at the State University of New York at Cobleskill, tells Mental Floss, "Meat is basically made of bundles of muscle fibers wrapped in more muscle fibers. As they cook, they squeeze together and force moisture out," as if you were wringing a wet sock. Hence the incredibly simple equation: less moisture means more dryness. And since the converse is also true, this is where brining comes in.

Your basic brine consists of salt dissolved in water. How much salt doesn't much matter for the moistening process; its quantity only makes your meat and drippings more or less salty. When you immerse your turkey in brine—Ryan Cox, an animal science professor at the University of Minnesota, quaintly calls it a "pickling cover"—you start a process called diffusion. In diffusion, salt moves from the place of its highest concentration to the place where it's less concentrated: from the brine into the turkey.

Salt is an ionic compound; that is, its sodium molecules have a positive charge and its chloride molecules have a negative charge, but they stick together anyway. As the brine penetrates the bird, those salt molecules meet both positively and negatively charged protein molecules in the meat, causing the meat proteins to scatter. Their rearrangement "makes more space between the muscle fibers," Cox tells Mental Floss. "That gives us a broader, more open sponge for water to move into."

The salt also dissolves some of the proteins, which, according to the book Cook's Science by the editors of Cook's Illustrated, creates "a gel that can hold onto even more water." Juiciness, here we come!

There's a catch, though. Brined turkey may be moist, but it can also taste bland—infusing it with salt water is still introducing, well, water, which is a serious flavor diluter. This is where we cue the dry briners. They claim that using salt without water both adds moisture and enhances flavor: win-win.

Turkey being prepared to cook.
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In dry brining, you rub the surface of the turkey with salt and let it sit in a cold place for a few days. Some salt penetrates the meat as it sits—with both dry and wet brining, Cox says this happens at a rate of about 1 inch per week. But in this process, the salt is effective mostly because of osmosis, and that magic occurs in the oven.

"As the turkey cooks, the [contracting] proteins force the liquid out—what would normally be your pan drippings," Yanisko says. The liquid mixes with the salt, both get absorbed or reabsorbed into the turkey and, just as with wet brining, the salt disperses the proteins to make more room for the liquid. Only, this time the liquid is meat juices instead of water. Moistness and flavor ensue.

Still, Yanisko admits that he personally sticks with wet brining—"It’s tradition!" His recommended ratio of 1-1/2 cups of kosher salt (which has no added iodine to gunk up the taste) to 1 gallon of water gives off pan drippings too salty for gravy, though, so he makes that separately. Cox also prefers wet brining, but he supplements it with the advanced, expert's addition of injecting some of the solution right into the turkey for what he calls "good dispersal." He likes to use 1-1/2 percent of salt per weight of the bird (the ratio of salt to water doesn't matter), which he says won't overpower the delicate turkey flavor.

Both pros also say tossing some sugar into your brine can help balance flavors—but don't bother with other spices. "Salt and sugar are water soluble," Cox says. "Things like pepper are fat soluble so they won't dissolve in water," meaning their taste will be lost.

But no matter which bird or what method you choose, make sure you don't roast past an internal temperature of 165˚F. Because no brine can save an overcooked turkey.

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