Is this the most genius way to cook a sweet potato? Molecular biologist turned food writer Nik Sharma thinks so. Nik and host Kristen Miglore also discuss turnips, super tasters, and how to navigate virtual socializing.
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Kristen Miglore (voiceover): Hi. I'm Kristen Miglore, lifelong genius hunter. For almost a decade, I've been unearthing the recipes that have changed the way we cook. On The Genius Recipe Tapes, we’re sharing the behind-the-scenes moments from talking with the geniuses themselves that we couldn't quite squeeze into the column or video: the extra-genius tricks, the off-road riffs, and the personal stories that actually have nothing to do with the recipe that week.
Kristen: Hi, Nik.
Nik: Hi, Kristen.
Kristen: How are you?
Nik: Pretty good, how are you?
Kristen: Good enough. I do want to jump in with this Genius Recipe, your Baked Sweet Potatoes with Maple Creme Fraiche. Can you tell our listeners what this recipe is and what problem you hope for it to solve?
Nik: The roasted sweet potatoes in my book–you take sweet potatoes, you roast them in the oven and you roast them half and half. That's what I call it, half and half, where basically first you steam it covered. So you take advantage of the moisture inside the water that's inside the cells of the sweet potato. As it heats up, that helps soften the fibers. When you roast sweet potatoes to make a pie, you want a really smooth texture. And if you don’t have that, you have that fibrous texture that is unpleasant to eat in pies. So I had to figure out how to remove that. And it turns out that if you wrap them up, the moisture inside the vegetable basically takes care of that by destroying those fibers. Those fibers inside are basically carbohydrates. Most of them are insoluble carbohydrates and steam helps destroy that structure. So you’ve got this creamy texture that comes about.
And then for the other half of the cooking time, you remove it and you cook it uncovered in the oven. What that does is, this is something really fascinating that I discovered. It turns out that when sweet potatoes are roasted, you get at least 14 to 15 new flavor molecules that are never created otherwise if you steam, microwave, or boil them. Why not take full advantage of what you have?
Kristen: It really is both the creamiest sweet potatoes that I've ever made myself. and the only sweet potato where I ate the whole thing and I felt like I didn't need anything else.
Nik: Exactly!
Kristen: So the steaming is mostly for texture, and then the roasting is to bring out those flavor molecules?
Nik: Right, yes. Another thing that I didn’t mention that steaming does. And this happens with almost all in this, like starchy vegetables like carrots, potatoes, sweet potatoes, is that steaming? It helps break down starch also inside. Starch is basically composed of long chains of sugar molecules called glucose. And glucose is one of the sweet sugars that is present in table sugar. That's also adding to the sweetness, but to a pleasant degree,
Kristen: Did you try a bunch of different sweet potato cooking methods before you landed on this one?
Nik: So I have a sweet potato pie in the book, and it actually started out with that. And I wanted to research why–that smell, that vanilla smell–kept coming back at me. So I went back to research papers that had looked at this in food technology. And they had done these spectroscopic analyses and literally compared all the molecules that came out and said these were the concentrations that came out. And I said, oh my gosh, I don’t really steam sweet potatoes and I know why now. I've never microwaved sweet potatoes. This is why I honestly just moved to roasting them every time. And this makes sense to me now that someone has given me numbers. That to me with solid evidence to say this is a method that I need to do more of in my kitchen. But I also can share this knowledge with other people so they can take advantage of it, too.
Kristen: That's absolutely what first grabbed me. It was the note that you had on those extra flavor molecules that come out with roasting. I have microwaved sweet potatoes when I need to feed my daughter when I'm trying to get us as many different flavors as possible. When I taste them, they do taste very flat. I love that your research is telling us exactly why that is.
Kristen: (voiceover) This is The Genius Recipe Tapes. We'll be right back.
Kristen: So, Nick, just like you did in Season and just like you did in this particular recipe, The Flavor Equation is so full of flavor combinations that I've never seen before, but I immediately want to eat. As you were deciding on the recipes for this book, what was coming first for you–the science or the emotion?
Nik: The tears, the emotion, I guess because I was trying much.
(Nik and Kristen laugh)
Nik: This book, oh my God, it made me cry so much. It was very easy for me to write the science chapters for this cookbook. When it came to the recipes, I was struggling because I couldn't figure out how to build recipes to teach the principles of those taste chapters. Because in this book, all the recipes reside under different tastes. I'm talking about how to experience all these different tastes, from savory to saltiness, to sweetness to bitter to sour. And then how do I showcase those to people in a recipe?
And it was such a struggle. You make a big recipe list when you write a cookbook, and then you go through it and then you start culling things that don't work. Then you go through a second phase when you are actually testing and creating things and you say, this sounds nice on paper, but wow it's terrible. Then there were experiments also that I wanted people to see. Because one of the things I advocate is fun. I really want kids to see something that I love - that cooking and science kind of go hand in hand. It's basically the same thing just under a different guise. And so how do I do that?
One of the examples is the Shishido Padron Peppers in the book, which are blistered. Then I wanted to teach the concept of umami synergism, where you have two different types of umami molecules that come together and then you experience greater umami in your mouth. The recipe talks about using soy sauce and then using bonito flakes. Both have different umami molecules, and when they come together, you have this explosion. So practically teach that to people. Because that’s important to me in a cookbook. Especially when trying to talk about food science. I don't want to throw theory at people because a theory is not that sexy for everyone. But actually teaching people to see how it's unfolding in their own hands in the kitchen is a much easier way to drive concepts home, which is why in science we have labs.
Kristen: But then how did you marry all of the things that you learned in your science classes with this really key emotional aspect that you talk about, which is not really present in a lot of food science books? How did that factor in? I mean, was that always a part of what you wanted to talk about in this book? Or did it kind of come out through your research?
Nik: When I got into the career of food writing, all my editors started to encourage me to write about my emotions related to food. In the headnotes, in the essays. And I felt like this is such an important part of how we behave, it would be foolish for me not to kind of see what had been done in research. There is a lot of cross-modal research happening on flavor and how people behave and how all of that ties in. I said you know what, this affects flavor and research has shown that it does influence even the taste we experience for different foods, and it affects the decision-making process. So I felt it would be kind of silly for me not to include all this.
Kristen: And the part that I really connected to as well was where you were talking about negative experiences with food impacting your taste for them. Being forced to eat certain foods when you were a child, basically you never really want to eat them again. Can you just talk a little bit more about what you've seen in your research about that?
Nik: One of the things that happen with children, starting with babies—babies first experience their first taste molecules when they're in the womb inside the mother. Lots of those molecules go through the bloodstream. When they come out, then breast milk is the next source for them to experience that. One of the most interesting things that I learned was that salt receptors actually don't form or don't develop properly until a couple of weeks after the child is born. And so the taste for salt actually comes much later in life. So the mother is the person that introduces the flavor molecules [to the child], from sugars to savory. What's really interesting, these are the molecules that actually provide us energy through life. So that's what you're being primed towards. And then as the child grows up, you're experiencing different things in your environment.
Part of it is culture. You know, people like me, I was born in India. So my flavor profiles that immediately come to mind are those that I experienced as a kid in India. And then my mother comes from a Portuguese colony, so her food was much more European influenced. So that plays a huge part in my cooking. feel like all these influences we experience in life prime us to how we eat as adults. Some of us don't like things. I don't like certain Indian vegetables because my parents forced me to eat them. And even now my mother asks, do you eat them now? And I said, no, I don't buy it, I don't bring it in my house because I'm traumatized by it. I remember talking to a spice store owner. He told me that when little kids come into their stores, they're so overwhelmed with the smell of spices that some of them start crying.
One of the reasons for that is when you're young, the number of receptors that you have for taste and aroma is high. And then at a certain age, I think in the late teens, they start to drop. And then as you get older, they keep dropping. So if you then start to appreciate things that maybe you wouldn't. So I feel as an adult now, I have a wider palate than I did as a child.
Kristen: Do you think you'll ever get to the point where your most loathed vegetables will work for you?
Nik: Probably not. I mean, I've always tried to like turnips. But I've never created a turnip recipe because I hate the sight and smell of turnips. Yeah, I don't see that happening anytime in my future.
Kristen: What was the situation in your childhood that set up this relationship with turnips then?
Nik: The trauma has, well I’m free from my parents' clutches of trauma. But I think one of the things we're most disappointed about is the way they cooked it, and then you would think it had some texture. But it's not! They would cook turnips smashed, breaded, and everything and say it was delicious and it never was. It stunk. It also was never a potato because as a kid, I really like cabbages and potatoes. And I used to go and think it was like a nice smashed, fried potato breaded or whatever it was, it was never that. It was always this damn turnip. They would say you have to eat it. And it was so ugh. So no, it's not something that I plan to overcome and I have no desire to climb that hill. We’re done.
Kristen: It’s just over, turnips.
Nik: It never began!
Kristen: I had some similar experiences when I was a kid. I didn't really eat salad until I was in junior high because I had a couple of very early experiences, I think at preschool, and then later at Girl Scout camp, where they served me a pile of like iceberg lettuce just covered in blue cheese or ranch dressing—really strong flavored, creamy dressing. And I was so distraught. I didn't want to eat it at all. And they made me take three Brownie bites and just I remember the shame and the fear. Then I didn't eat any salads with dressing until I was 12 or 13. And only then, it was cultural pressure the other direction that made me start to dip my toe in because I looked around and everyone else was eating salad.
Nik: Sometimes when parents force their kids to eat things, I think there are better ways to go about it. Another thing that I didn't know, and I'm sure my parents still don't know even if I told them about this. Bitterness is governed by genetics—a lot of people just don't like bitter foods, and you can't convince them otherwise. I hate saying genetics because it kind of sounds like a destiny thing, But not all of us will like something because of culture, environment, and of course, genes.
Kristen: That's so interesting. What was the research on genes showing? Was it specific only to bitterness? Or were there other taste preferences?
Nik: So there is a subset of the human population, which is called supertasters and these people generally have certain mutations in their DNA in genes that make them sensitive to bitter foods. So they've been discovered for coffee, for polyphenols, and all these other chemicals. The only bitter substances, from what I've learned, that people really enjoy, even if they hate other bitter foods, are the things that are addictive, like chocolate and coffee. Because your brain says it's going to get this caffeine reward and so you can compensate. It kind of builds that up. I think it's very fascinating to see genetics at play because I love the science of it all. A lot of people who do not like bitter foods moved to sweeter things. So I've been told, this is much more qualitative, that a lot of pastry chefs could be supertasters because they prefer sweet things. And a lot of them do not like bitter things. I do not drink beer, much to the vexation of all my friends. When we used to go to bars. I never drank beer and I would just say it's just so bitter, I can't handle it. I got myself tested and It turns out I have a situation where I just cannot handle bitter foods, but I prefer sweet things all the time.
Kristen: You are so much speaking to my own heart about this because I studied this a lot in grad school. I was very obsessed with what causes picky eating behavior. You being a supertaster doesn't square with a lot of the things that I have read about supertasters because you do seek out strong flavors in other ways. What do you think about that?
Nik: So one of the things is that I think it's also because of culture. I really think it's because of culture because if I didn't grow up in an Indian family or if I didn't grow up in India, I've always considered what is the other situation? One of the things I've gone back to see what kind of foods my parents cook? One of the things I was very fortunate about is that my parents came from two different backgrounds, so the food was always different. They never actually tried to say, today we're only going to cook North Indian food, today we're only gonna eat Goan food. It was just, whatever we're gonna cook, you're gonna eat and call it a day. Like turnips showed up sometimes. And I think that's very important because of that mental block of having a walled-off thing, that you can only do this. It doesn't exist in my mind because my parents didn't build that wall. And they didn't do it on purpose. Whatever they were cooked, you had to eat and call it a day.
The other thing is that in Asian countries in general, and even in Central and South America [countries], you'll notice no one really pairs anything from the same ingredients. No one really does that. It's more of a Western concept– cool flavors are always put with cool. If you look at Malaysian food, you look at Indian food, you look at Mexican food, even African food, for that matter. There's like a whole explosion happening in your mouth, things that you would not consider pairing come together. No one's going in with this preconceived notion that it has to taste like the singular ingredients. That's another important thing. I feel like sometimes when we write recipes, we say, ginger and cardamom and everyone's expecting to taste ginger and cardamom in that recipe. If they don't taste it, they get upset.
How about you walk in and you taste it with the mind saying that I'm gonna taste something new? And it doesn't have to taste like any of the individual ingredients. You see that repeatedly in recipes from Mexico as an example. When you have a chicken mole, you don't really expect to go and taste bitter or sweet. You're expecting to taste something quite savory. And even though most of us know that cocoa goes into it, chocolate sometimes goes into these recipes. And I think that's where having an open mind comes in. I keep saying open mind. Not trying to pair things by some flavor pairing rules. I actually don't like that concept at all, I think it's very restrictive. You have much more freedom when you're saying okay, let me see if this works, okay, doesn't work, let’s try something new. I'm always hesitant to–some of the scientists who believe in that probably hate me for saying this–but I just feel uncomfortable kind of propagating something that has such a heavily Western, one-sided view when the rest of the world might be doing something else. And I think I want to see more of that, which is also one of the reasons why I wrote this book. I did not want to write a science cookbook based on what was already known. On very Western driven recipes. Even though there's mayonnaise in the recipe, it comes from my lens, it's got strong Indian influences in it.
Kristen: THat’s so beautiful. And it really is such a reflection of all these things in your life and things that are important to you and that comes through. And it really makes your book stand out. Nik, this Thanksgiving and just this year, in general, is obviously so unprecedented and unlike anything we've seen before. What's your Thanksgiving going to look like?
Nik: It's gonna be very small, just me and my husband, which is fine. It'll be nice to kind of spend some one on one time, and cook one meal and then eat it for a couple of days. So I'm excited about that, that I don’t have to cook. It’s a strange thing for a cookbook author to say, to not want to cook every day. But no, I’m excited because I think one of the things that COVID has taught me, that this pandemic has taught me. We've actually been doing a lot of one-on-ones with the friends that live in different countries and even family. It's actually been a really fun way to connect with them for a short period of time. And this is kind of nice, you have an exit strategy. So you hang out. You have all the fun stuff. And then as soon as the conversation starts to get a little awkward? Okay. Gotta go.
(Nik and Kristen laugh)
Nik: Gosh, I'm so terrible at this.
Kristen: (voiceover) What are you cooking this Thanksgiving? If you stumble on something Genius, I would love to hear about it at genius@food52.com. Our show was put together by Coral Lee, Emily Hanhan, and me, Kristen Miglore, If you like The Genius Recipe Tapes, be sure to rate and review us. It really helps. See you next time.