Short Wave - Want Juicy Barbecue This Fourth Of July? Cook Low And Slow

Episode Date: July 1, 2024

Perfecting your grilling technique ahead of the Fourth of July? Chefs will tell you that cooking is not just an art — it's a science. And the spirit of summer barbecues, NPR science correspondent Sydney Lupkin brings us this encore piece about how understanding the chemistry of cooking meat can help you perfect your barbeque. It's all about low and slow cooking. This story was originally reported for NPR by Gisele Grayson. Read her reporting.Curious about other science powering the things you love? Email us at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hi, shortwavers. I'm Sidney Lepkin, NPR Pharmaceuticals correspondent, in for Emily and Regina today. And bringing you something way off my usual beat. We got two cases, so about 160 pounds of pork butts that we're getting ready to throw in a smoker. That's right. Smoking. Meat, that is. Smoking means cooking at low temperatures for a long time. And it turns out smoking isn't just an art. It's a... science. George Loving got into smoking meat while tailgating at his son's football games. We went to college. I said, you know, I'm going to get one of those big smokers made and pull it

behind my truck and just tailgate in the parking lot. And somebody said, George, why don't you, you know, do it as a business? And that's how smoked at barbecue catering was born in Washington, D.C. George says Brisket, the lower chest of the cow, is one of his favorite cuts. It's the epitome of smoking because it takes the longest. You put it in the smoker and you just let it cook. You always want to stay around that 225 to 250. So a good barbecue is juicy. It practically melts in your mouth and it has that smoky flavor with a bit of char. And it's not something I've ever pulled off myself because achieving that magic requires for one equipment I don't have in my apartment, but it also takes a long time cooking at low temperatures. I've seen some brisket's cook in eight to ten

hours, I've seen some take 14, 16 hours. It's something you just don't rush. And when it's done, it's done. Today on the show, a meat metamorphosis, the chemistry behind transforming a tough cut of meat into juicy deliciousness. I'm Sidney Lepkin, and you're listening to Shortwave from NPR. Okay, so you've gone to the supermarket, picked out your favorite cut of meat, let's stick with brisket, and you're ready to get smoking. The first thing to remember is that cooking is really a bunch of chemical reactions. That is taking substances and changing them by combining them with other substances, applying heat, gloopy cake batter turns into firm, fluffy cake, raw eggs become opaque,

and raw meat can be turned into really tasty barbecue. So let's get into it. Meat is muscle, and in muscle, there are a lot of proteins. And we learned in high school biology that the proteins in our muscles are actin and meosin, right? That's what helps us to flex and move around and do all these things. And so every cut of meat has actin and myocin in it, no matter what. That's Matt Hardings. He's a chemist at American University, and he wrote a book called Chemistry in Your Kitchen.

He says the tougher cuts of meat also have another protein called collagen. The purpose of collagen in our muscles is to make them resistant to strain. All these cuts of meat that have lots of collagen, they are coming from proteins and animals that are constantly moving, right? So the legs of a cow, right? Chicken legs, chicken thighs have more collagen than chicken breast. And so the way we cook those cuts of meat reflects the amount of collagen that they have in them. Collagen is basically shaped like a coil or a spring. Cooking on low heat over a long time gently uncoils it. The magic of low and slow is that when you cook collagen the right way, it breaks up into gelatin.

and gelatin makes jello, right? And you go from something really firm and chewy and not appetizing it all to fall apart tender. This is the chemistry lesson at the heart of making really good smoked meat. Break down the collagen by cooking the meat for a long time at low temperature. Like Matt said, it's what smoking experts call low and slow. What you're trying to do with the low and slow is really take a very tough cut of meat. and making it melt in your mouth. You're really going to be cooking that piece of meat over 12 hours.

Keeping your fire going for that amount of time for a brisket takes a real steady hand and a lot of patience. Low and slow isn't just about breaking down collagen proteins. It also helps keep the meat from drying out. So moisture control is another place where you need to be very patient and have a nice, steady hand. If the temperature gets too high, you are going to dehydrate your meat. a little bit, right? All that water's going to come out and all the muscle fibers are going to pack tighter and tighter and tighter with one another. On the other hand, you also don't want your cooking chamber to be too moist either or something called bark doesn't form. And no, it's not tree bark,

but it bears some resemblance to it. Bark is the tasty crust that forms on the outside or surface of the meat, a kind of browning, and it needs just the right amount of moisture to form. So the bark is a product of the my yard reaction. The my yard reaction, is likely my favorite chemical reaction. And what that is is a reaction between a sugar and a protein. Lots of our foods have sugars and proteins in them. And so anytime you see any sort of browning while you cook something, that is the myriad reaction.

But my yard reaction makes all these crunchy, savory, flavor enhanced things. So when we get that myard reaction, and that crispy, crunchy, savouriness, it just makes our food taste so much better. Now, what about the actual smoke in smoking meat? If you're cooking with wood, you want to make sure the smoke is barely visible. White billowy smoke is no good because it gives the meat a harsh, smoky taste. So it all comes back again to cooking low and slow. If your temperature is too high, you're taking that wood and just you're burning the bejesus out of it, right?

And so everything is turning into soot and carbon dioxide and water. But if you do it at a low temperature, those big, enormous molecules in trees, right, that hold the trees together, lignin and cellulose, and especially the lignin, that lignin breaks down slowly. You get chunks, like little parts of that molecule fly off. And those molecular parts give the meat different flavors. As long as you burn your wood slowly and at a low temperature. Again, if you torch it, if you've got huge flames leaping off of it, all those molecules that you're trying to make from your lignin will break down. Spice, smoke. And those little parts of those molecules are things like guayacol, which is spicy and smoky, or vanilla, right, which tastes like vanilla.

Different woods impart different flavors depending on the amount of lignin in the wood and how it's cooked. Woods that have lots of lignin will have a very hearty smell to it. So something like mesquite, mesquite has a really strong aroma to it, and that's because of the amount of lignin it has. Some other woods that aren't as lignin heavy are not going to be quite so bold. There's also a thing called a smoke ring, which is the pink coloring that you get on the outside of the meat when it smoked, under the bark. It starts with a protein and muscles known as myoglobin that carries or stores oxygen until we need to move. Then it burns the oxygen and some sugars.

Myoglobin is also what makes our meat, our muscles red, right? It's what gives it its red color. Normally when you cook myoglobin, what happens is, we talked about the unraveling of these proteins, that myoglobin unravels, changes its shape, and it turns from red to brown. We're used to seeing that when we cook meat, whether it's smoked or not,

but in the chemical reactions in smoking, the smoker creates nitrous oxide too. Nitrous oxide binds where the oxygen would normally go. There's an iron atom in the middle of your myoglobin. And so the nitrous oxide goes onto that iron atom, and it doesn't change color when the protein unravels. It stays this beautiful pink color. And so when you smoke your meat and do it right, you get this sort of nitrous oxide infused.

meat, and that's what gives it that pretty pink color. Fun fact, nitrous oxide is also laughing gas, like at the dentist. If we were to huff a bunch of nitrous oxide right now, right, or whatever, right, our cheeks would flush pink because the nitrous oxide. And the same happens with carbon monoxide, too, right? Your cheeks flush pink because all of that, the myoglobin or even the hemoglobin, right, that carries oxygen in our blood is going to take that, those gases on instead of oxygen. turns a bright pink. That's the one way that people who are asphyxiated with CO or something like that, a corner will say, well, this person has a high, like a really bright pink blood or bright pink muscle. We can tell that they've been poisoned with carbon monoxide. Okay, so I know that

took a turn. Back to barbecue. The pink smoke ring on the meat actually doesn't have anything to do with the flavor, but it's still important. It indicates that we have cooked our meat at when we're doing low and slow at an appropriate temperature and an appropriate pace. We haven't heated it up too quick. We haven't gone too slow with our cooking. There's sort of a temperature range at which you're going to make the smoke ring and do it nicely, right? Make a very nice smoke ring around the outside of your meat. And so if you've done that, right, it's just an indication that you have cooked your meat properly. So how do you know when the meat is done? That is an excellent question. And this is another big difference between cooking food fast and doing the low and slow. When I'm cooking

a steak, the best way to know it's done is to use the meat thermometer and see, well, is it the temperature I want it to be, right? So medium rare is 125. Medium is just over 130, right? It's a little bit different with low and slow cooking. I'm always testing texture. What does it feel like? And that's the best way to do it. With ribs, it's hard to do because you can't like sort of jab at the ribs too much. Something like pulled pork, it's super easy, right? You kind of take your pork and take your fork and will it shred that pork right away. If it starts to shred, you're golden. And it falls apart because of all those protein changes that happen in just the right way, thanks to cooking low and slow and picking the right wood. So when you're smoking meat,

you're seeing science and action. One of the things that I love about smoking, there's a couple kinds of cooking that just fascinate me from the standpoint of an academic chemist. People, when they step into a kitchen, whether it's making bread, whether it is cooking pancakes, whether it is brewing beer, whether it's making barbecue, you are doing such incredible chemistry. Whenever you're doing that, you are a chemist. A big thanks to pitmaster, George Loving, and chemist Matt Hardings for their expertise on low and slow cooking. And to shortwave very own meat smoker, Giselle Grayson, for this reporting. This episode was produced by Britt Hansen and Burley McCoy and edited by Sadie Babbitts. Giselle Grayson and Susie

Cummings checked the facts. The audio engineer was Josh Newell. I'm Sidney Lefkin. Thanks for listening to Shortwave from NPR.