Never Put Meatballs on Spaghetti, with Samin Nosrat

0:01I'm snorting. I'm snorting already. Already? We haven't even started. What's gonna happen?

0:11Science Chats with our favourite nerds. Yeah. Hi, I'm Wendy Zuckerman and you're listening to Science Versus. Today on the show, the wonderful chemistry and science of food. Yeah, because, you know, even if you've never set foot in a lab, you are doing a little bit of science every day when you add a little salt to your pasta or you cook your vegetables, or even if you make a Betty Crocker cake, you are doing some really cool science. And one award-winning chef who's thought a lot about all this is Samin Nasrat. She's the author of the best-selling book, Salt, Fat, Acid, Heat. She has a new book out.

0:54It's called Good Things. And I've wanted to get Samin on the show for ages because she makes me think about cooking and the food that I shove in my mouth in this completely new and very nerdy way. And so that's what we're talking about today. The science of cooking. Plus, why you should never put meatballs on spaghetti. My interview with Samin Nosrat is coming up just after the break.

1:33Welcome to the show, Samin. Thank you so much for coming in. Thanks so much for having me. Growing up in San Diego, I've heard you say, and you write about it a little bit in the new book, that you never really felt like you belonged that much in San Diego. Can you tell us about it? Well, I mean, my family's from Iran, and my parents came to San Diego sometime in the mid-70s. In 1979, there was a religious revolution in Iran, so a lot of people sort of sensed that coming. and my parents uh my father's side of the family um was a practice of religion called the bahia faith and they were persecuted so they all fled and were religious asylees and my mom like came after followed my dad here and so i was born here and this and i was born here to a family who wasn't entirely, like, willingly, you know, in San Diego.

2:29Like, it was just, right, there's the trauma of leaving your homeland behind. My, you know, we, there was, in ways I'm sure I can't imagine and probably many ways I witnessed, there was racism and sort of Islamophobia directed at us and to my parents. And I'm sure that they had a pretty clear sense of, like, not feeling very welcome or belonging here. And I also think because they didn't leave, especially my mom, did not leave Iran thinking she'd be gone forever. My mom would say things like, you know, when you go, when you leave this house, like, you're stepping into America, but when you step over the threshold into the house, this is Iran, and you're going to, like, behave like an Iranian child, right?

3:17and um i my mom it was so important for her to instill in us a relationship to the place that we were from and one of the ways that she did that sort of most powerfully was through food and so and i have always loved to eat so like and the food is good you know and your mom's an amazing and my mom's a great cook yeah um and i remember there were things where like i would bring persian food to school for lunch and people you know it was the classic like immigrant kid being like ew ew what's that the smell of the whatever in the lunchroom and they would have been eating some disgusting peanut butter and jelly sandwich and so or like americans gonna get mad at me saying that but it's just oh you think it's oh yeah i actually love pbj too but I know it's a very American thing, though.

4:09Like, other cultures are like, what are you people doing putting that stuff in your mouth? But then, and what's funny is now, like, you know, 40 years later, Persian food and a lot of Middle Eastern, Persian food, a lot of times, it gets appropriated by non-Iranian cooks onto their restaurant menus, where it gets a sort of a glam, like a makeover. and um and on the one hand i'm really happy for more and more people to have exposure to our foods and in other ways it makes me so mad like it's like you want our food you know what i mean you want to eat the crispy rice you or there was a drink i used to have it's like a summer drink called secanjabin which is like a it's kind of like maybe um an early relative of a shrub so So it's like a vinegar and sugar syrup that's boiled down with mint.

5:05And you make this like really thick, very fragrant minty syrup. And it's so tangy and refreshing. It's kind of like the original Gatorade in a way. Like, right? It was just one of my favorite childhood things. And I remember having like a water bottle of it with the mint leaf in it when I was a kid. And some people, like little kids at school were like, ew, gross. Like, what's in your water? You gross, like alien. Yeah. You know? And now, of course, like every like hipster bar has shrubs on their menu. You know, so there's just this way where I, it's like an extra pain, a level of pain where I'm like, this is yet another way in which like our humanity is not recognized.

5:46And you just like take from, you pick and choose what you want. And this is like historically been done against all, you know what I mean? Like Americans love tacos, but hate Mexicans. So, like, it's just, it's not unique to us, but it does hurt when I feel that. You talk about in your new book that as a kid, cake mixes became like a Betty Crocker cake, became kind of this simple. My obsession. Yeah, your obsession. What was it about the Betty Crocker cake or those cake mixes? I mean, my mom was really, she was very committed to like an organic only, like low sugar, you know, like sort of a very hippie like rules in the household for the children of like, we're only eating fresh fruits and vegetables.

6:38as we shopped at the vegetable, at the, like, hippie co-op. And so it's not that we were never allowed dessert, but even when she went to get us the birthday cakes and things for occasions, special occasions, they came from, like, the finest European bakeries, right? And they were covered in chocolate shard, in chocolate shavings, and they were just this, like, dense chocolate cake. And I just never wanted to eat that. I wanted to eat what all the white kids had. Like, at the bake sales, I wanted to eat the fluffy yellow cake with chocolate frosting. Like it was soft. And I would have never been allowed to have that.

7:15That was like not okay. It never entered our home. And so this is again going back to the like outsiderness. I think it became a symbol. Like the yellow cake in a way became like this symbol of fitting in. And so, and there is something just extraordinary about cake mixes. and the very light, like incredibly tender texture, which almost feels like it's like a space, like astronaut food or something, because it's not, it's like doesn't seem naturally achievable. And so I sort of became obsessed as a young cook and with like, there must be a way to achieve some sort of like lightness because every cake I, you make a cake with butter and it's dense and heavy.

8:03You make, you know, you could use the same exact ingredients as what's in the, you think is in the yellow cake cake mix. You could follow the Joy of Cooking, Martha Stewart, anybody's like classic yellow cake recipe. And it would still come out quite dense. And I just wanted this lightness. Yeah. How do the cake mixes do it? What? So the, well, my, this was a many year journey for me and I didn't know the science of it. But over time, I learned that like butter is made of, you know, it's made of fat primarily, but also milk solids, which are like proteins and water. It's an emulsion. And so when you cream butter and you are like, you know, whipping sugar into it to make this like kind of light texture, that's that you're aerating the butter.

8:49And that's the main source of lightness in a cake. Like, butter is in this kind of emulsist. It's like a magical state of emulsion. That's why it's like it can be on your counter and it's a solid, right? Yeah, yeah. It kind of has this incredible range of temperatures at which it stays in this solid emulsified state. Which is why it's like that amazing thing when you, like, spread butter, cold butter on your warm toast. And it's like, kind of like some of it melts, but some of it's just soft still when you bite into the soft butter. And so you have that. And the thing about it is the melting point of butter, like chocolate, is very close to human, our body temperature.

9:29So it's so pleasing the way it melts. It melts on the tongue in this really, like, amazing way, right? Yes. That's like part, you eat a piece of chocolate and, like, part of the pleasure of it is it's just, like, melting on your tongue. And so butter is kind of this miracle ingredient. But also, like, you have to understand there's water in there. And when water and flour combine and start mixing, that's when gluten strands start forming. And gluten is like a protein that leads to chewiness and toughness. It's what you want to develop gluten in something like a crusty loaf of bread so that when you cut into it or bite into it, you get that like sourdough chew.

10:11You know what I mean? Yeah, yeah, yeah, yeah. But that's not the thing you want in a cake. In a cake, you want it to like crumble and dissolve tenderly. That's what I want. is like tenderness on my tongue. And so you want to prevent gluten from forming, which is why they use lower protein, lower gluten flours, things like cake flour and pastry flour to make cake. And also when you have oil, and so fat inhibits gluten formation. It kind of coats flour and it makes, you can think of it almost like it makes it slippery. So the flour is not going to combine into long gluten strands because it's kind of like lubricated by this outer layer of fat.

10:50Right. So then the thing that the way cake mix is made industrially, like at some point I kind of went and learned about that. And it's made in these, you can think of them like massive food processors, just like huge machines where they combine all the dry ingredients with shortening, which is a solid fat. It's a solid oil, right? And they mix, and because it is solid but it's soft at regular room temperature, they can put shortening in there and coat the flour, you know, mix it without any—they're pre-oiling the flour in the cake mix so that when you bring it home and you add your oil and your water, less gluten will form.

11:38And it's done for so long and on such an industrial level and so carefully that you can't see the fat, right? You don't see any of that. You can't. It just looks like flour and cocoa powder when you dump out a chocolate cake mix. But that's what's happened to it is like the flour has already been pre-coated with fat. And so I just was like, huh, I'll never be able to do that. I don't want to make a cake with shortening. That's not going to taste good. Like I want it to be with butter, but I don't know how to do this. and then at some point i stumbled into um which is so funny because maybe i if i had been looking well like if i had been more method i'm not i'm not saying i'm like methodical in any of this i am not a scientist but this is where are we at two decades in this journey right now yeah which honestly maybe if i had been more methodical i could have solved this a lot sooner because literally there is a book it is it is like a it is a legendary book called the cake bible like honestly I could have just looked in the cake but come on come on you think like in Lord of the Rings Frodo could have just looked at the map you know got the journey totally totally so like Rose Levy Berenbaum is kind of this extraordinary just well like queen of cakes and she wrote this book called the cake bible so whereas when a typical yellow cake A typical sort of homemade cake starts with room temperature butter that you're whipping sugar into, and that step is called creaming.

13:07Reverse creaming sort of mimics what's done in the cake mix industry, right? Where you take your flour and your sugar, and if you're using cocoa powder, whatever your dry ingredients are, and then you take very soft, but not so soft that it will separate into water and fat, butter. you take butter that is just at the exact right temperature and you work it into the flour very slowly in your mixer or your food processor in such a way that like by the time you've worked all the flour in it actually just looks or all excuse me by the time you've worked the butter in the flour just looks like a dry ingredient it's kind of amazing it is this but it's all about having the butter yeah I mean Rose did it and so and it was one of those things where I was like this was here all along and I feel like such an idiot.

13:59And also I felt like a genius because the first time I made it, people came over and I was like, I did it, you guys. I made a homemade Betty Crocker. And people were like, I don't know. And then they started eating it. They're like, oh my God, it really tastes like it. So it felt like that was truly a miracle that I thought. I know there were so many bad cakes on the way to that cake. In the middle. But you did it. I did it, yeah. Okay, so to continue on with your journey, a lot of people, including me, sort of first met you after you wrote the book Salt, Fat, Acid, Heat, which then became this Netflix documentary, which is amazing, the book, the documentary.

14:44For those who haven't come across it, what is the overriding thesis of Salt, Fat, Acid, Heat? Yeah. Yeah. It's basically that if you can sort of grasp why salt, fat, acid, and heat are important elements and understand, you know, their function in the kitchen on flavor and on texture and how to balance them and how to use them, that they will work as sort of the four points on the compass for you as a cook, no matter what you're cooking. And so whether or not you want to follow a recipe, paying attention to salt, fat, acid, and heat will enhance the way that you feel independent, are able to cook instinctively, understand what's going on underneath the maybe steps one through six that someone else lays out for you, so that in case you need to substitute something, you understand why that vinegar was there and why it would work or wouldn't work to replace it with lemon juice.

15:52Yeah. So with salt and fat and acid, those are all tangible. Fats come in many forms. There's oils and butters. There's animal fats. And same with acid. Comes in many forms. But heat is kind of this like ineffable, intangible thing. But as a young cook, I kind of realized that was how everyone around me that I was looking up to and learning from really oriented themselves in the kitchen on any given day. And they were not always consulting cookbooks and recipes. The things we were always tasting for were salt and fat and acid. I think about it every time I have avocado on toast because I'm like, Samin would be so proud of me.

16:29I'm toasting my bread. There's my hate. I've got my avocado and then my salt and my lemon. Like it's the most basic version. But I always think of you. I mean, I am so glad. And that's the thing I always say is like, this is actually a lot simpler than you think. it's just some jargon you have to like wrap your mind around, but we all naturally do this. I mean, all of these things are things our palates have evolved to seek and to enjoy, right? And so like if you are a person who goes, has ever been to a taqueria and has garnished your own burrito or taco with sour cream and or cheese and or salsa, you know, or guacamole, like, and done it again and again until it tastes just right, then you're balancing the salt and the fat and the acid, right like you're doing it already and in um salt fat acid heat you talk about this story of working at shape honey which you've mentioned it's like this for those who don't know fancy restaurant in berkeley california where you got your start and having this moment where you realize that salt is not just the sidekick for pepper but actually can like completely reshape a meal if you try it and you you actually wrote um sorry if it's awkward that i'm quoting you no to you um but He wrote, if one lesson from this book stays with you, let it be this.

17:48Salt has a greater impact on flavor than any other ingredient. It really does, yeah. Do you know why that is? It does so many amazing things. You salt meat in advance, which is to say like a chicken that you're going to roast tomorrow. I would salt it today to give the salt plenty of time to be absorbed and be distributed evenly throughout the meat. That means like tomorrow when I roast it and I take a bite, I won't have salty skin and bland meat. I'm going to have an evenly, perfectly seasoned chicken, right? The salt has penetrated and gone all the way through. But also the salt will have worked on some of the proteins and ultimately leading to much more tender meat.

18:28It sort of disables some of the proteins leading to more tender meat. And that is like a crazy function is like just by salting your meat in advance, you will have a more tender meat. salt also on, it has a kind of an ability, if you think about a tomato, like slicing a tomato and you salt your tomato slices and you wait a few minutes and then you come back and you look and there's like all this water has come out, right? There's like the tomato's juicier all of a sudden. And you take a bite of that tomato and the one that has salt, even if it's just a little bit of salt, so little that you don't actually taste it to be saltier, your experience of eating that tomato is going to be totally different because what the salt has done is by bringing out not only water, but aromatic molecules out of the cells that it started to break down, that means with every bite, your nose is going to breathe in so much more aroma.

19:24But the vast percentage of our experience of eating is smell, not taste, right? The vast experience. So the more access we have to aromatic molecules, the more profound our experience of eating is going to be, right? The more like perfumed and profound, right? So you are always after like, how do I get those aromatic molecules? It's the same as like, why people, you know, tear fresh basil into the thing at the last minute. It's because you just want that smell, right? You want that, you want that smell as close to your eating experience as possible, right? The fragrance is what makes it sort of alive.

20:02And so salt, a lot of times sort of goes into cells, breaks things down. I was even surprised that salting correctly when cooking beans can make them more vibrantly colored? Yeah, totally. How does that happen? So what's happening when you have a very salty pot of water and a vegetable in it is immediately osmosis is going to start to happen in the pot, but also inside the vegetable, inside the cells of the vegetable. So it's going to start absorbing. In an attempt to reach homeostasis, right, it's going to start absorbing salt from the pot into itself and that's what's going to flavor it. And that means it's like holding on, right?

20:39It's pulling in minerals, right? It's in a state of pulling in minerals and not letting them out. Whereas if you cook your vegetables in under-seasoned water, then in an attempt to reach homeostasis, the vegetables are going to leach their minerals into the water and with their minerals, also the chlorophyll will get affected. They will be less vibrant and less green. Amazing. It's just a wild, totally, it's really wild and amazing. It's so incredible. Salt is so magical. So in the Netflix documentary version of Salt, Fat, Acid, Heat, you get to visit as, I guess for those who haven't seen it, I mean, visits the world and sees like all these places that kind of represent these elements.

21:24And for Salt, you visit the soy sauce factory. and um and i have heard you say that and you could see it you cry like a baby um i i wouldn't have said cry like a baby but i thought well since you what was so emotional about that place well for me so much of it has to do like that soy sauce in particular i also got very emotional in the parmesan in the parmesan factory um but and both of those foods are foods that have hundreds or even thousands of years of tradition being made the same way. There's so much knowledge. So the story of that soy sauce producer in particular is that it's one of the last remaining traditional soy sauce producers in Japan.

22:10And what makes it so exquisite is that it's aged for upwards of two years. Whereas if you think of like Kikoman or other industrially produced soy sauces, they're aged around three months maximum. So that thyme is, you know, and in any food that you're producing, thyme is often the most expensive ingredient. In addition to the two years of aging the soy sauce, this soy sauce is aged in these special barrels, these like huge wooden barrels that only one or two people are left in the world who know how to produce these barrels because they last close to 100 years. But as the industry has industrial, like, become so much more industrial, the need for that knowledge and for those barrels has disappeared, because Kikoman, just like an industrially produced soy sauce, is just aged in stainless steel casks, like, in the place.

23:07So the wood for the barrels is harder to find. The knowledge of producing the barrels is harder to find. And the barrels are part of the taste, right? There's microbes in that specific type of wood from that place that affect the way that that tastes. So it's almost like I knew in that moment I was getting to taste an endangered food, an endangered species. And Parmesan is not endangered, thankfully. But again, years of aging go into making a wheel of Parmesan. Hundreds of gallons of milk go into one wheel of Parmesan. So it's just, it's like this massive amount of work and, like, resources and time for one little bite.

23:51And that is what is so meaningful to me is, like, I love those things. I love that in my whole life. I love things that feel like the magic is sort of hidden a little bit. How do you make parmesan cheese? What are you doing with all that milk? What are they doing? Well, all cheese, all cheese. This is one of those things that blows my, I love dairy so much. Like I, what's funny is my girlfriend's lactose intolerant. And I'm like, oh God, I feel so bad. Like, like... But, you know, when I was a young cook, actually, working at Chez Panisse at this amazing restaurant, one of the things that really sort of blew me away was seeing these people, like, these incredibly experienced cooks, who literally knew how to make anything from scratch.

24:38And that sort of is a little bit of, like, what became my ethic, right? Like, how can I make this yellow cake from scratch, right? Right. And so, but one of the things that they didn't make from scratch, it already kind of surprised me that they made it at all, but they didn't make it all the way from scratch, was mozzarella cheese. So we would pull fresh mozzarella, we would get the curd from the local producer, and then pull it into fresh, like, balls that then we would slice and turn into, like, caprese salad or something else. And it is kind of this magic trick. It truly is, like, it turns into this, like, rubbery texture, and, like, it's very fun to make.

25:13I was like well this is amazing but why aren't we starting with milk right like we should be able to make we should be able to make our own curds get the cow yeah I was like this is the house I've made from scratch let's make this from scratch so God bless them this is like one of those things where I'm like only at Chez Panisse I decided to take this on as my project and I was you know probably 20 years old I had no culinary maybe they sometimes let me cut an onion like I had no culinary experience I had no business doing this. This is also very early internet. This is like 99, 2000. You have to remember.

25:47Okay. So you couldn't, there was not like a, there was not the internet where you could be like how to make mozzarella curd from scratch. There was not that. So I had to look it up in books. I went to the UC Berkeley, like food and cookbook science library, like sort of looked this up in books. And I found out the basic steps. I called a few cheesemakers who were friends of the restaurant. They all were like, do not do that. They were like. They were like, and I was like, I don't know what you're talking about. It's so simple. It's just milk and rennet and a little acid. Like, of course I can totally do it.

26:19And they're like, no, literally because it's so simple, it's one of the hardest curds, one of the hardest cheeses to make. Don't do it. So basically, this is all to say I spent like an entire summer wasting like tens of thousands of gallons of cheese, of milk, in an attempt to make mozzarella that like never. Also, because cheese, you have to have everything super sterile. Because it's basically, the whole point is, it's at bacteria growing temperatures, so you just have to make sure you're not growing the wrong bacteria. And so you can make people really sick in cheesemaking. People can die. So you have to sterilize everything, which is like, do not trust a 20-year-old in a restaurant kitchen to be making cheese that you want to eat.

27:06But one of the things that I learned was, oh, my God. Like, I would start with a gallon of milk and end up with, I don't even know, eight ounces, maybe eight ounces of curd. Wow. So, after the success of salt, fat, acid, hate, I thought you would be living it up, Simena, living your best life. um but you write in the in your new book it wasn't it wasn't it hasn't been exactly like that okay how have you no i mean i'm okay i'm okay now that's good but um yeah it was you know i was 38 when the book came out and when the and i was 37 when the book came out 38 when the show came out um and i'd spent most of my life till then much of my life till then being like quite sort of invisible in the world right like just had down doing my work um like sort of dying for acknowledgement for the hard work and then I went from one extreme of like being very sort of under scene to then being like very over scene yeah it's just that like it it kind of knocked me off kilter in a lot of ways yeah and I had to yeah I I like sunk pretty deep and depression.

28:26Yeah, you wrote that, like, the sense of joy that you'd always found in cooking and eating no longer felt attainable. Yeah, yeah. It was really, it was a very, you know, obviously during this time it was also, there was COVID. Yeah. There was, like, George Floyd murder. But ultimately, and part of it had to do with my dad dying and, like, watching my dad... Oh, I'm sorry. Oh, thank you. I was just, like, watching... this very complicated and kind of horrible person die a very sad, prolonged, complicated death. And my dad was such a chaos agent and created so much pain for so many people, and his last months were really awful for a variety of reasons.

29:18But part of sort of the, like, takeaway was that, like, he was alone, you know what I mean? like my brother and I were there with him as much as we could be, but like there was, and we were just in this sea of chaos that he had created during this time. It was so horrible and uncomfortable for all of us, including him. And I was like, this is the worst way I could imagine for somebody to die. It's just so lonely and sad and pathetic. And I kind of had this moment of being like, you know, when I'm on my deathbed, I want to look back and know that I made a life that was full of beauty and joy and friendship and connection and deliciousness and puppy dogs and gardens and, you know, art.

30:05And so once he died, I kind of was, I think this is pretty common, but I very much was sort of washed over with a sense of like, you only live once. You know what I mean? Like The sort of preciousness of time really sort of was like, I could see it so clearly in that state of grief. It was just like, oh, I've spent my whole life trying to be good and to do good and to win the affection of the people around me. And I've had this sort of voice in the back of my head being like, just put your head down, do good, do good, do good. Like I'm investing in a good bank account so that one day I'll reach some sort of like balance from which I can withdraw and be happy, you know?

30:47And I was like, oh, there's no day, right? There's no there that you get to. Like I have to, why am I making myself so miserable in the meantime? The meantime is all there is. Yeah. Like, and so I think I sort of have just changed as much as a person can change my policy about that of like, oh, I have to like, even if I'm on deadline and I feel really bad about being behind, which is all the time, like I still have to take a break and go have watermelon in the park with my friends. You know what I mean? Like, I still have to have a little bit of joy every day. And I still have, and a way that I can do that is this, like, simple act of cooking.