How To Keep Meat Juicy With Science : Short Wave How do you make the perfect stir-fry chicken without drying it out? Today, we answer that question with cookbook author and chef J. Kenji López-Alt and science! Host Emily Kwong talks to Scientist-In-Residence Regina G. Barber about velveting, a technique used to seal in moisture during high heat cooking. Then, some listener mail!

If you're hungry for more food-based episodes, check out our TASTE BUDDIES series.

How To Keep Meat Juicy With Science

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You're listening to SHORT WAVE...


KWONG: ...From NPR.

So a few weeks ago, I had a few of my closest friends over...



LU: Oh, my. Look at - what, what?

MCCOY: I know.

KWONG: ...Aka, some of the members of team SHORT WAVE - you may recognize the voices of Thomas Lu and Berly McCoy - for an experiment in the culinary arts.

REGINA BARBER, BYLINE: I'm kind of jealous I was on the wrong coast, but a culinary arts experiment - are you saying you tried to cook something new?

KWONG: That's right, Regina Barber, and I used all of my creative impulses.

Sliding off this pan like kids down a waterslide into the wok - whee, I'm going to be a dish.

BARBER: (Laughter) I love it.

KWONG: You know, you got to talk to your food. I sent my friends outside, so it was just me cooking with Berly, our cat Zuko...


BARBER: I love the name - go "Fire Nation."

KWONG: ...And possibly the most versatile pan in the kitchen - the wok.

BARBER: Everyone should get one.

KWONG: Seriously, we have a whole episode about woks coming out in a few weeks...

BARBER: Awesome.

KWONG: ...Featuring this guy.

KENJI LOPEZ-ALT: I'm Kenji Lopez-Alt. I am a he/him.

BARBER: Oh right, the cookbook author - "Food Lab."

KWONG: Uh huh.

BARBER: Doesn't he have those videos where he records his cooking from his head?

KWONG: Yeah, something like that.

LOPEZ-ALT: The GoPro was sitting in the kitchen, and I was about to cook something, so I just stuck it on my head, and I was, like, looking at my YouTube channel, and I was like, oh, this one video I have has, like, a million-something views, and it was just making a grilled cheese sandwich with a GoPro on my head.

KWONG: Kenji is all about demystifying the process of cooking. He peppers the pages of his cookbooks with science explainers so people can understand what's happening in, let's say, the wok, and why. So today, for the first time in a while, we have a SHORT WAVE Micro Wave.


BARBER: Ooh, I love our Micro Waves - our mini episodes with a little bit of science, and it's followed by some listener mail.

KWONG: That's right. And today, in this microwave, we're going to break down the science behind a cooking technique called velveting for making the perfect stir-fry, where the meat stays tender and the veggies are crisp.

BARBER: Velveting - it's not just for upholstery.

KWONG: That's right.

BARBER: (Laughter).

KWONG: You're listening to SHORT WAVE - the daily science podcast from NPR.


KWONG: So, Regina, what is your relationship to the cooking pan known as the wok?

BARBER: I actually have two woks. One is pretty old and nicely seasoned. I use woks to mostly, like, stir-fry vegetables and make big noodle dishes.

KWONG: Oh, it sounds so good. I have a wok that was salvaged from a thrift shop, and it's perfectly seasoned, too - such a find. We use it for stir-frying, steaming, simmering. But there's this thing that can happen in wok cooking where you're making stir fry, right? And your vegetables are crisping up all nice, but you're simultaneously drying out your meat.

BARBER: Yeah, I actually hate that.

KWONG: Yeah. And I always wondered, like, how, in Chinese restaurants, they kept the meat so tender.

BARBER: Totally.

KWONG: It provides that contrast with the rest of the stir fry. And the answer, my friend, is velveting.

LOPEZ-ALT: The name is called velveting because it gives the meat a very tender, velvety texture because it's already essentially cooked through.

KWONG: So think about restaurant stir-fry. You know how the chicken is kind of slick and, like, shiny?

BARBER: Yeah, it's. It's almost, like, unnaturally smooth.

KWONG: Well, that's because it has gone through this velveting process, where you marinate lean meats like chicken or pork loin or fish in a slurry of cornstarch and pre-cook it.

LOPEZ-ALT: So it actually makes the stir-frying process easier because you don't have to try and cook the meat through. It's ready to accept the sauce because it already has this layer of cornstarch on the outside. So all you have to do, then, is stir-fry your aromatics and vegetables, add your meat, add your sauce, and toss it all together. And it - you know, essentially, you do it to lean meats to give them that very, very sort of tender, velvety texture.

BARBER: It sounds so delicious.

KWONG: Right? What I learned from Kenji is that if you prepare this velveting marinade, it kind of acts like a sealant, protecting the meat from the direct heat of the wok and keeping the juices inside.

LOPEZ-ALT: As the meat cooks, and if it's exuding any juices from the inside, those juices, instead of going out in the pan and sort of steaming away, they get trapped in this layer of egg white and cornstarch.

BARBER: I want to make this now. Tell me more about the velveting marinade. Like, what's in it?

KWONG: OK, so Berly and I made Kenji's velvet chicken with snap peas - very simple. First, we cut up some chicken...


KWONG: ...And we coated it in a marinade of egg whites...


KWONG: ...Cornstarch...


KWONG: ...And a water-based liquid.


KWONG: You can use soy sauce or stock or Shaoxing wine.

BARBER: Like rice wine, right?

KWONG: Yeah.

BARBER: OK, so why those ingredients specifically?

KWONG: Well, the water-based liquid provides flavor and color. The egg whites - upon cooking, they create that loose matrix of protein, kind of setting up around the meat and protecting it from the heat. But the real star in this marinade is cornstarch.

BARBER: Love it.

KWONG: Cornstarch is raw starch. It's just extracted from the endosperm of corn, and it has this amazing property.

LOPEZ-ALT: Starch, essentially - like, it swells in water. And so it thickens water, and it turns it into this, you know, sort of, like, gel matrix as it heats.

KWONG: A single grain of starch can swell to 30 times its original size...


KWONG: ...Upon contact with heat. So when you coat chicken with a marinade based in cornstarch, it prepares the meat to later absorb sauces from the stir-fry and keeps the meat's juices trapped inside during cooking.

BARBER: This is super interesting. I love his phrase gel matrix. So after you marinate the chicken in this, like, cornstarch slurry, like, what's next?

KWONG: All right. Next is kind of a high-wire act of heat and courage. You want the coating to stick evenly, so the next step is basically to precook the meat in boiling water or oil.


KWONG: So, yeah, we're putting the chicken that's coated with the cornstarch into hot water. This is called passing through. And in Chinese restaurants, actually, they do it with oil. We're just doing it with water because - a little healthier, maybe a little less scary.

BARBER: Ooh. Wait - what did the meat, like, look like after it was passed through?

MCCOY: I would have never thought to do this. This is...

KWONG: Right?

MCCOY: ...Such a...

KWONG: Doesn't it look like chicken you get at a Chinese restaurant, though - how it's kind of soft and doughy and spongy?

MCCOY: Totally.

KWONG: Then it was time for the wok.


KWONG: We added the chicken to a bath of delectable lemon ginger sauce...


KWONG: ...Those snap peas, and the final dish was...

Oh, my gosh, it's so good. Ooh.

BARBER: (Laughter) I'm still jealous.

KWONG: All I'm saying is that, by the power of cornstarch vested in me, I will be velveting my proteins for my wok from here on out.

BARBER: I think I will too.


BARBER: But for now, Em, ready for some listener mail?

KWONG: I'm ready. Let's hear it.

BARBER: Listener Leah Maria Park (ph) writes, (reading) your piece about Chien-Shiung Wu really moved me. She's just so inspiring for me, as an Asian-read girl - which I think she means people assume she is Asian. She goes on to say, (reading) I also relate to Jada because I still don't know a lot about my grandma's life story, who passed when I was 13. I was just not interested in much of it at the time, and now I wish I had asked her. Thanks for bringing the story to us.

KWONG: Hmm. Oh, that's beautiful.

BARBER: It is beautiful.

KWONG: I also lost my grandmother very young, and, yeah, sometimes I think this kind of reporting is definitely, like, in her memory, you know?


KWONG: What is the next letter?

BARBER: Yes, OK. So Maggie (ph) writes about our episode with Wendy Zukerman and Blythe Tyrrell from Gimlet's Spotify podcast "Science Vs."

KWONG: Woop, woop (ph).

BARBER: That show is trying to counter misinformation in its current season, and we had them on to talk about it. Maggie writes, (reading) I just wanted to let the SHORT WAVE team know how much I thoroughly enjoy your podcast. My two favorite science podcasts together. It would be great to hear more collaborations from both shows, like all your favorite superheroes teaming up. Happy face.

KWONG: This is hilarious. I love being compared to, like - like we're The Avengers...

BARBER: Right.

KWONG: ...Out there fighting misinformation together. Wendy, call me up.

BARBER: Yes, but we're like the Avengers that, like, record in our closets. It's...

KWONG: Yeah, we're like nerd Avengers who sit still...

BARBER: It's less active.


KWONG: ...You know?

BARBER: But we still do good.

KWONG: We do.

BARBER: We still do good.

KWONG: Thank you all so much for listening. We will be back with more Micro Waves in the future. If you have an idea for one, email us at


BARBER: This episode was produced by Berly McCoy, edited by Gabriel Spitzer and Gisele Grayson, who is also our senior supervising editor, and fact-checked by Margaret Cirino. The audio engineer for this episode was Gilly Moon.

KWONG: Andrea Kissack runs the science desk. Edith Chapin is vice president and executive editor-at-large. Terence Samuel is vice president and executive editor, and Nancy Barnes is our senior vice president of news. I am Emily Kwong.

BARBER: And I'm Regina Barber. Thanks for listening to SHORT WAVE from NPR.


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