Pushkin the late twentieth and early twenty first century. This era we've just been living through has obviously been this period of incredible technological change. But in terms of technology transforming everyday life, our era is not unprecedented, which is to say our era is precedented, I would argue, In fact, I have argued that in terms of everyday life, there was an even bigger technology driven transformation in the period one hundred years earlier, in the period of the late
eighteen hundreds and early nineteen hundreds. That period saw the coming of cars and planes, the spread of telephones and the electric grid, and the spread of refrigeration. Refrigeration allowed us to preserve and transport food like never before, and in fact wound up really completely transforming the way people eat the food we eat every day. I recently interviewed a journalist named Nikola Twilly who just wrote a book
on refrigeration and how it changed us. The book is called Frostbite, and one of the things the book really made clear is how refrigeration changed daily life in this
really profound way. Niki describes this transformation in microcosm via the work of this husband and wife sociologist team, The husband and wife visited a town in Indiana, first in eighteen ninety and then again in nineteen twenty five, and they talk about the different ways life has changed in this town, and Niki focuses on the way refrigeration changed the way people eat.
In eighteen ninety, what they found is that the city had two diets. It had a winter and a summer diet, and then the winter diet was just really meet start carbs, pastry, potatoes, things like that, and the only sort of vegetables to enliven it were either root vegetables, turnips, cabbages, apples you could store in the root cellars, or things you had pickled or preserved from summer. But fresh fruit, green vegetables, leaves, berries, none of that.
And you talk about how people would be sick essentially, like everybody in town would get sick by the end of winter.
Yeah, they called it spring sickness. Today we'd call it sort of a prescore buttic syndrome.
So like about to have scurvy, like about.
To have scarvy, not full blown scurvy, but yeah.
The mild scurvy that everybody got every winter exactly. And so then these academics, these sociologists come back in the nineteen twenties once, you know, refrigeration is clearly not ubiquitous by that point, but it's in the world. And what do they find, how do they find? The diet in this town has changed.
It has changed utterly. They can buy oranges and lettuce shipped from California, and bananas shipped all the way from Central America.
All but the very, very poorest.
Are beginning to be able to enjoy some of the sort of what I call the supermarket in the US today, permanent global summertime. You know, you can have anything you want at any time. Spring sickness has been alleviated. No one speaks of spring sickness anymore. And it's totally a you know, the older generation remember it, the younger don't.
I'm Jacob Goldstein, and this is what's your problem. My guest today is Nikki Twilly. Her new book, Frostbite is
full of useful insights into science and markets and technological change. Also, the book has just a bunch of good stories, including but not limited to the central role of beer in human history, the shockingly complex technology that goes into the bags of salad greens on the shelf at the grocery store, and why the technological frontier and refrigeration may mean that we don't need to keep so much stuff so cold. My conversation with Nikki started more or less at the beginning.
Humans have been able to control fire since before we were even modern humans. That goes way back heat.
Heat we got, heat came early all.
Over it, and some people argue that's what made us human, you know, the ability to cook and then feed our big brains, et cetera.
Cold much trickier.
All the great minds you know, Newton, Galileo, Robert Boyle, all of the scientists that you've heard of. Leonardo da Vinci tried to figure out where on Earth cold came from. But yeah, seventeen fifty five, a Scottish doctor, almost as a party trick, figured out how to freeze water. His A pupil of his had noticed that if you put a thermometer in ether, which evaporates very quickly, and when
something evaporates it pulls heat away. The energy of turning that thing that liquid into gas pulls heat away, so you get a cooling sensation. He used a bunch of different liquids to try and make this work. He used chili oil, he used brandy, he used menthol he you know, he was going for all the sort of ones that give you a tingly sensation logic. But in the end he did manage to create a setup that froze water
for the first time. First it was this was the first time seventeen fifty five that humans were able to make cold on demand. And he was just like, well, this seems kind of interesting, but I don't really know what to do with it, so others should investigate. And no one did anything for one hundred years because it was like, what are we going to do with this? It's a party trick.
Yeah, that part is wild, right, It's like, here's this giant breakthrough, We're ready, and then crickets.
It's you know, there's I quote a line from Robert Browning in the book, humanity's reach had exceeded its grasp. We could we had figured out how to do something, but we didn't know what to do with it. You know. It just that, yes, the picture of what you could do with cold wasn't there yet, right.
And and you write about that, right. You point out that in the eighteen hundreds, the first kind of industrialization of cold that emerges is not from this new technology but from a guy just selling ice, just like cutting ice out of frozen lakes and putting it on ships
and sending that around the world and selling that. And it's not until like one hundred years after that Scottish doctor inventing refrigeration that this guy in Australia, James Harrison, who you write about, He's like, oh, maybe refrigeration could be you know, a business, So tell me about that piece of it. Tell me about James Harrison.
So, as with many things with technology, a few different people are fiddling about with us at the same time and making prototypes, and it's to do with who actually gets it going. But James Harrison, son of a Scottish salmon farmer, went to emigrated to Australia, as many British people did at the time, worked as a printer. He was actually a journalist, wrote and printed the local newspaper
near Brisbane, and he printing in Australia's summer heat. He noticed that if he wiped ether over the type, then the ink didn't smudge because of that cooling effect. Again, it would evaporate off and at the time natural ice was reaching Australia, but it was expensive, the amount that had melted by the time it had got to Australia in the distance, etc. It was expensive and it was rare. It was like, I bet I could use this either thing and build a refrigeration machine. I mean, he blew
himself up several times. There was many sets of eyebrows were lost, but he ended up with a functioning machine. And he was the first one to sell a refrigeration machine, something that was capable at first, not of cooling things, but of cooling water, of making ice. This is another funny thing, like humans didn't think, oh, we could just cool a room. They thought they were only used to natural cold.
Ice is cold. If we want something to be cold, let's freeze water and make it ice. Right, That's like step one exactly. And who is his who is his market? Who's he selling ice to brewers?
One hundred percent brewers? You know some people credit beer with being you know why humans got into agriculture and domesticating grain and settling down forming civilization because we wanted to drink.
Yeah, you mentioned that in passing in the book. That's like one sentence in the book. And I read it and I thought, is it true? I mean, nobody knows if it's true, but like, how plausible is that theory?
It's a pretty plausible theory.
Like this is a theory that is subscribed to by many archaeologists and reasonably backed up by residue in pots. People were definitely making alcohol almost the first thing they did with their grains.
What is the Homer Simpson line? Beer the cause of and solution to all of our problems? Pretty much but perhaps historically true, right if you think of the rise of agriculture, as you know, the creation of many many problems and then the solution to many many problems exactly.
And ditto refrigeration.
So yeah, so why are brewers the first market for artificial refrigeration?
So you can make beer without refrigeration, it's just and if you can drink it warm. I grew up in England and people do still it's not my taste, but you.
Know, technology, one hundred years of technology notwithstanding.
Notwithstanding it, did you know why? It's actually a flavor thing. Things taste more bitter when they're warmer, and if you are looking for that taste in your beer, as British people are, like oh, I'll have a pint of bitter.
They say, well, then warmer is better. But the point is that lager was having a boom in popularity, in particular because Germans were emigrating everywhere and bringing with them their love for lagger and lagger yeast doesn't really function particularly well above fifty degrees and so in the Laggering caves in Saint Louis and Brooklyn it was getting too hot in summer to make beer. And I mean summer is when beer tastes best. So this was a crisis.
And the brewers were huge consumers of natural ice. But then you know, there would be natural ice famines. If there was a warm winter, there wouldn't be enough natural ice to go around. The price would go up, and also increasingly as cities got bigger, and in an era before you know sanitation, the natural ice was getting polluted and really dirty.
So yes, it.
Seeing of ice in a cave in a basement in Brooklyn in eighteen seventy like that is nasty.
There was a certain in the summer, certain funkiness, certain funkiness, let's put it that way. So they were the early adopters of this, this refrigeration technology. The first refrigerating machines ever sold were both to breweries, one in London, one in Australia, and they are the ones who also pioneered the whole idea of like, wait, we don't have to make ice, we could just cool the cellar. And that was actually a brewer in Brooklyn figured that out.
Sort of cutting out the middleman. Right, there's this moment which is kind of beautiful in a like history of technology way, where they're like, we want the room to be cool. We know ice is cold. We've got this machine, and it just takes what years? How long does it take before anybody figures out that you don't actually need to melt water into ice put the ice in the room, you can just cool the room.
About five years?
Wow? Yeah, like a generation. Yeah, the technology is right there. It's just like an insight problem exactly.
They did just I mean, if you're used to thinking of cold as a property of ice, yea, then seeing it as not is sort.
Of a leap. Yeah. No one in history has ever used a machine to cool air exactly until somebody.
Yeah, until until you know, this brewer in Brooklyn came along and did that. And it was a huge improvement. You can imagine like ice melts, it's funky, it's disgusting. Now you have this clean, dry refrigeration machine just cooling the room. The only problem was these were all prototypes. They're massive, they use very explosive chemicals, and they're steam powered, so they're constantly blowing up. They're unensurable, they're unreliable. Every
single one is unique because they're all prototypes. So it just took Whenever I sort of look back at this history, I have to remind myself it took a long time because there was a lot to figure out. It was a French monk who eventually figured, oh, if we put the compressor, the thing that sort of compresses the refrigerant so that it can evaporate again, if we put that in an enclosed container, that's going to work much better
because then it won't you know, keep breaking down. And he did that because he wanted, you know, to chill the communion wine in the south of front, so you're adjacent. It's all alcohol in the end.
And by the way that you know, that insight that the monk had of using a hermetically sealed compressor, like that's basically the way referreerators work today, right, Like, that's the basic idea.
Still, everything about the early refrigerator is basically the same as the refrigerator we use today, except we're using electricity rather than steam, and the chemicals we use are you know, we're not using ether anymore. We're using various things with extremely long names, but otherwise the principle, the mechanics identical.
So you're right about the way people take this technology and extend it so that you can keep trucks cold and you can keep ships cold. Right, and then we get this world, this thing that becomes called the cold chain, which is a world where we can keep food cold from the moment you know, a vegetable is picked or an animal is slaughtered, basically until the time I pull it out of my fridge or my freezer to cook it. And once we have this cold chain, people start to
kind of rethink food in a bigger way. And there's a few pieces of that of that kind of rethinking that I want to talk about from the book. So tell me about this thing called the low temperature research station.
No one had any clue what temperature things should be at to last the longest, but not freeze and not you know, or not turned brown or whatever. No one had any clue like what should be stored with what and for how long. All of that had to be figured out, and so the Low Temperature Research Station was really the first attempt to do that. It was set
up by the British government post World War One. Britain is a very small little island filled with a lot of people, and even back then it imported most of its food and as German you boats were sinking ships bringing food from the colonies. The British government were like, huh, we should figure out how to keep a supply on hand, sort of a reserve. This is a matter of national security. We can't just do a just in time system, you know. And so they set up this Low Temperature Research Station
where a bunch of scientists tackled everything. I mean, they looked into meat. In the book, I spend most of my time looking at how they studied apples. Apples were
a huge fruit at the time. This is before the rise of the banana, so to speak, and the apple was kind of it and apples would come from the colonies and need to be stored, and there was you know, a whole set of research going on into how do you store apples, And it's not just a matter of temperature, as it turns out, it's also a matter of what the apple is breathing. And this was the thing I
didn't really realize until I wrote this book. But when you harvest produce, it's still alive, it's still metabolizing, it's still breathing, and like us, it has a certain number of breaths left until it dies.
When you say breathing, it's taking in what it's not is it oxygen? It's so, it's not the usual.
It's not it's not so distance No, huh.
So what what is it taking in? And what is it putting out?
It's taking an oxygen and putting out carbon dioxide, just like us.
Just like us.
Yeah, it's just they're just like us, and just like us, they have a certain number of breaths before they die. We know this about ourselves so that we don't tend to think about.
It very much a lot, to be honest. But whatever. So what do they figure out about apples at the at the Low Temperature Research Station.
Well, they figure out that you can make an apple breathe much more slowly if you reduce the oxygen levels. And they figure this out by putting apples in a in a vasoline lined coffin, they call it sitting them in there. You suck out the oxygen, and there's this, there's this sort of it's a finely tuned thing. You can't remove all the oxygen because then the apples will just ferment, and that is then it's all over your cider. Yeah, so you need to get it low enough so that
they're still breathing, just breathing as slowly as possible. And that actually varies by apple species. So you might be able to take a Pink Lady down to you know, zero point five percent oxygen, but a Red Delicious only down to two percent. But the point is you're sort
of putting the apple into almost suspended animation. It's just breathing as slowly as possible, and it's it's sort of like if you play the podcast on like half speed, it takes twice as long, while the apple that is breathing at you know, half speed, lives twice as long. And so they figured this out, put it into commercial practice,
and this is how apples are stored today. This is why you can go to the store right now, which is before the apple season starts, and by a Washington State apple and it will be juicy and fresh and also nearly a year old.
And is temperature also a part of that formula to sort of induce this hibernation.
Oh yeah, you have to bring the temperature down. And again that varies based on the species. But cold's main method of preserving things is to slow things down. We know this, like we are slower in the cold. Bacteria and fungi are slower in the cold. Apples are slower in the cold. You're just adding the atmospheric effect to it as a sort of additive, so it slowed down even more.
Still to come on the show the technological marvel that is a plastic bag full of lettuce. So apples are a good one. I mean, there's a lot of specific innovations for different foods. But another one I want to talk about is lettuce. Tell me the lettuce story.
For a long time, lettuce had to be grown near where it was consumed. And then once ice you know, ice making machines came along, well that's when California got into the lettuce business and the Salinas Valley became the largest ice producing uh you know area of the world, second only to New York City, and the amount of ice they made there because they were icing down all the lettuce, and that meant the lettuce itself had to change because you know, the soft Boston bib type they
don't do so well when they're ice. You need something sturdy, like oh, an iceberg, which gets its name supposedly from the fact that when these crisped lettuces were jammed into railcars and topped with the load of ice and retopped, you know, every couple hundred miles along the railway, it would look like icebergs were coming, you know, like a train car set of icebergs was coming towards you.
Yeah, you wrote that. Before this time, the kind of lettuce that we call iceberg was called Los Angeles right, Los Angeles lettuce and like kind of I mean, I guess people like it, but like not a real lettuce lettuce right if you want your like green vegetables, icebery lettuce is notably not that green. And I mean, as I read the book, it just takes off as lettuce because it's the lettuce that you could send across the country. In a railcar full of ice one.
And that happens again and again with the refrigeration. It happens with apples too. The apples we have on our grocery store shelves are the apples you can store in controlled storage. Lots of very tasty heirloom varieties do not do well in controlled storage. They can't be kept that long,
and so we don't see them on supermarket shelves. It's just a it's sort of an ecological filter where things that cannot be stored in this mass market industrial refrigerated way no longer make it onto the grocery store shelves.
But people are figuring out ways to store more things in this mass market industrialized way, which is what happens with lettuce right, which is why we can get so much lettuce now. So like any in particular bagged lettuce, to my surprise, turns out to be like a wild technological breakthrough.
I know, this is a thing where you just think, oh, it's convenient, whatever, it's plastic bag, that's nice, maybe they washed it, big whoop. And actually it turns out that that bag that you just kind of crumple up and throw away is this super high tech respiratory apparatus for the lettuce leaves, and it all came about surprisingly recently, and what it really is is that the bag is essentially a miniature plastic version of a big controlled atmosphere
Apple warehouse. It's the same idea. The plastic is actually not just plastic. It's several layers of what is called differentially permeable membrane, which is basically just plastic with different kinds of holes in it to let different gases through at different rates that you have designed when you specified the plastic and manufactured the plastic, and you glue all that together minimum kind of seven layers, as many as twelve to get exactly the atmospheric blend you want in
that bag of lettuce. So at first it was just chopped lettuce, and it was the idea was just keeping that in a controlled atmosphere. Then it was like, you know, what, people want a salad, not just one kind of lettuce, So we need to throw some arugula in there and some baby spinach. And to do that you have to calculate how fast each of those leaves are breathing, and they breathe at a different rate, so baby spinach. Because
it's so young, it's breathing very very fast. En dive is like kind of sturdier, more chill breathing more slowly. You have to mix your leaves in the correct ratio to get an even kind of breathing pattern. So the spinach breathing super fast. You put enough and dive in to kind of chill things down and take the overall bags metabolism down. So it's this entirely. You think, oh, they put in too much and dive. I don't like that. No, it's all engineered to.
And when they're like different. You know, you can buy a bag of baby spinach. Is the plastic bag for the baby spinach like different than the plastic bag for whatever, the pre mixed Koleslaw or whatever.
Yes, one hundred percent, because they're delivering a different atmospheric ratio. I mean, this is the most high. It's using Cold War era submarine technology, which is when people started spending so long under the water that you know, people had to figure out how to deliver controlled atmospheres.
It's like a submarine. It's like a submarine for greens basically exactly.
Yeah, they and the guy who invented it who's still alive.
Has anyone heard of this man?
No, you know J's name, We haven't even said it. Say the name.
Jim Lug, James Lug. It's like this bold step forward for salad that has been completely forgotten. And I'm guilty of this as anyone else. Like you bring a bag of salad home, if it doesn't fit in your crisper drawer, you kind of open it to squish out some of the air and put it in there. Now that I know the effort that has gone into creating that little atmospheric bubble, I'm like, I'm so sorry.
Sorry, Jim. What about the so that the soft play bag is what we're talking about, They also sell salid now in the like hard plastic clamshell. Is that some crazy technology that I don't even know about.
No, that's been that's been.
There's actually less effective, but it's been flushed with more of an inert gas to the best of my knowledge. But it's but actually not as high tech. The bags are more high tech.
Huh. And do the bags work better? Do the bags preserve the greens longer than the hard shell?
Yeah?
Huh, not intuitive?
I know now you know, so one of the things.
That's interesting to me in the book is you seem ambivalent about refrigeration. You spent ten years on the book, and like, clearly you admire a lot of the people who figured things out, but you seem, yeah, you seem ambivalent about the effects of refrigeration on humanity in the world. Like, how do you weigh how do you weigh the effects of refuge?
Well, yeah, so, first of all, I think the important thing is to weigh it. And here's one thing I came to realize as I worked on this book is that refrigeration is just so taken for granted as a central sort of you know.
This is how we eat.
It doesn't get evaluated for its costs or benefits. It just is you know, it's one of those things like air where it's like is air good or bad?
You know, we need it.
So I actually thought it was important to say, well, you know what, it's a very recent technology, extremely recent. Wasn't commercialized till you know, just over one hundred and fifty years ago, wasn't commonplace till a century ago.
If that, like, this is a very.
Recent transformation of our food system, why are we assuming that it has to be that it is, you know, inevitable. When you're starting to write a book, you go and
look at see has anyone else written about this? And I went I went to the New York Public Library and I looked at the most recent book on refrigeration, and it was from the nineteen fifties, and it said, well, like, refrigeration's great, and you know, human progress continues, and no doubt the next food preservation thing will be along shortly. No one at the time thought refrigeration.
Was the end, uh huh, and yet it has sort of become the end.
It's interesting because I feel like mid century was that with a number of things, right, like with air travel comes to mind famously. Right if the fifty years from whatever, nineteen hundred to nineteen fifty, nineteen ten to nineteen sixty were like this incredible thing, and then we basically got the same thing now that we had then.
Yeah, a little better, but you know, like moderate iterations, but the same thing. And the reason, h I think it's important to look at. I mean, there are a few different reasons. One is the super pressing one, which is refrigeration actually turns out to have a huge climate change impact. The refrigerants themselves are super greenhouse gases. A lot of the time the power to make things cold, you know, the energy required to make things cold is a huge burden. And if the rest of the world
refrigerates like America does, which it doesn't right now. You know, the US is sort of Europe as well, but unique in having a cold chain of the scale we have.
It's sort of a microcosm of the broader like, oh, there is a developing world. Reasonably everybody wants to have the same standard of living we do. But if that happens, we're screwed in terms of climate change, among.
Other things, completely screwed in.
The absence of other innovations, at least exactly.
And whereas people sort of seem to recognize that with like, oh, hey, if everyone has a car in Africa, we're screwed, they aren't talking about it when it comes to well, if the entire food system is refrigerating.
World, if the cold chain that we have in the developed world becomes global.
Yeah exactly.
Okay, Well let's do this way. You wrote a book, you spent ten years. What has happened has happened? On balance, you think we're better off or worse off for refrigeration.
I think better off as long as we figure out what to do about the climate change aspect of it.
So let's let's talk about what comes next. Yeah, what people are trying to figure out. It is an excellent point that seventy years ago, everybody's like, surely the next cold making, surely the next refrigeration breakthrough is imminent, and nothing right, So what are people working on? What is the frontier of refrigeration.
It's very underfunded. And that's also before you think about you know, there's cooling things more sustainably, or there's preserving food. Differently, when refrigeration was first, you know, introduced, people were thinking that the big preservation breakthrough that people needed to feed cities was not going to be cold cold was you know,
this fleeting natural ephemeral ice thing. There was no way it would work at scale, so they were looking into all sorts of you know, fumigation, coatings, shredding things and drying them. You get the invention of the bullion cube as a way to say, oh, how do we kind of extract the nutritional value of meat and at least
preserve that. So it's at the time people were aware that you know, preservation could take many forms, and I think that's one of the things I look at in the book is like, what if the future of you know, some things have to be cold. Ice cream has to be cold, beer has to be cold in my book, but you know, an apple doesn't actually have to be cold, it just has to be preserved.
Most of refrigeration is not keeping things cold so that we can eat them cold. It's so that they don't spoil exactly.
So if there are other ways for them not to spoil, well, then you could have a vastly slimmed down cold chain. Or listen, we've built our system in the US, it is what it is. You could say, well, hey, in countries that haven't built their cold chain yet, maybe they could build this leaner, meaner model in the same way that you know, they didn't get checkbooks, they went straight to digital banking on their phones, and they didn't get landlines,
they went straight to cell phones, et cetera. So could we find better preservation solutions if what we're trying to do is keep food fresh that don't require cold chain where possible.
What are people working on in terms of preserving food without cold so.
Some people are working on high pressure process. So if you can just apply enough pressure, you can sort of squeeze out the bacteria and fungi. This works with meat apparently quite well. It's expensive right now. It's very much at the experimental stage. This is not something that is done like commercially right now. Where is the one that I went to see is done commercially right now, which is a coating. And so it's funny, it's like what
goes around comes around. All of these you know, pressure, coating, fumigation, like, all of these things were things that were thought of in the seventeen fifties and now are being tried again, and coatings is one of them.
Really, the trick.
With this one coating company appeal is they're taking the same logic of the apple warehouse and the salad bag. They're just putting it on to the produce item as a nanoscale coating that is made out of food particles. It is exactly the semi permeable membrane. But your salad bag is it's just not plastic. It's just sprayed directly onto your cucumber and it's controlling the cucumbers breathing that way.
I mean it seems cool, but as you describe it, it sounds like a thing one does not want to eat.
That's where you're wrong. Licked, I licked the produce with this on. I'm here to tell the tale.
So, like, what is actually going on? What are they doing?
It's a different formulation for each fruit and vegetable because you're trying to create a different modified atmosphere.
And you.
Create this formulation, there's a lot of trial and era you spray it on. It's nanoscale. Part of how it works is people think of it as like wax or something like it's a thick layer that's blocking things. No, it came out of research into solar panels that was all about how if they dry at different rates, they like assemble slightly different at the nanoscale, have different You know, a solar panel can be like twice as efficient if
you'll let it dry two times more slowly. So this is a similar It's out of this same thin film polymer physics, and you just have to spread it on and dry it a certain way. It assembles with these properties. It's nanoscale, so like undetectable made out of food waste and what it's doing. Is this exact same thing that the salad bag is doing, which is slowing down how fast that piece of produce breaths so that it takes its allotted number of breaths over a longer time. And
it's kind of astonishing. I like, I, you know, I was went in as a skeptical journalist and then I saw the bell peppers that had been sitting out for eight weeks at room temperature, and I feel, we all know that after eight weeks at room temperature, a bell pepper is not in great shape. It's you know, it's no longer something you want to eat. These bell peppers with the you know, the nanoscale coating, they weren't crude to tabared ready, but they were definitely stir fry, were
they They were. They were a little sad looking, but they hadn't gone And eight weeks, yeah.
Two months a long time for a bell pepper to sit on the counter.
No killing.
So are they are they in out in the world now? Like, are there fruits that you can buy that have this coating on them?
There are?
In fact, Walmart just announced that it's ditching plastic on its English cucumbers in favor of appeal.
This coating Okay, yeah, the English cucumber they sell that, that's the like the hothouse, the long the long one and far more tasty cucumber that it is like shrink wrapped, right, it has like, yeah, it's basically shrink wrapped when you buy it. And so Walmart's going to start selling it with this lipid coating instead of plastic exactly.
And it works better. It like keeps the product fresher.
And this is one of the fascinating things about it because over time, refrigeration has totally changed our understanding of what freshness means. It used to mean something that had been harvested or slowtered really recently and really nearby. It was something to do with time and distance. Then refrigeration changed all of that because suddenly it could have been slowtered six months ago and looked like it was slowdered yesterday. So the definition of fresh changed, and what appeal does
is sort of say it could change again. It could be fresh doesn't have to mean refrigerated. It could just mean with more of the nutrients and the flavor that it had when it was on the plant. It could be a chemical definition, not a you know, not something that we at the moment. The definition of fresh is it needs to go in the fridge, right, I mean that's or it comes from the fridge. That's how people
think of freshness. It could be. It could be to do with the actual youth relative of the fruit and vegetable itself, how few breaths it's taken.
We'll be back in a minute with the lighting round. Let's finish with the lightning round.
Okay.
In the book, you cite a number of publications with amazing names, including, but not limited to, Food Engineering Magazine, Container Management Magazine, Palette Enterprise Magazine, and Food Technology Magazine. If I am going to read one trade publication, any trade publication, which one should it be?
Does it have to be one that's still in print? Because the old school ice in refrigeration, which was imprint from like the eighteen eighties to the nineteen, I want to say, twenties thirties, is I could spend all day reading that. It's incredible.
Tell me more, what with the John McPhee of ice in refrigeration.
None of the articles assigned, all of them are delightful. They are entire articles about how cold affected Napoleon's Army, for example. It's just a much more wide ranging look at you know, cold is this sort of phenomenon.
Yeah, I love.
It's the magazine for people who are into cold exactly.
So I'd say start there.
What's your favorite thing that you can eat because of refrigeration?
Oh well, I mean this is a hard call between. I mean, if it's eat ice cream obviously, although you know, if it's drink, then think of all the world of cocktails that previously didn't have ice in them and are now so so good.
I mean, there's even things that like aren't cold, but like mangoes. Like I live in New York and like, theoretically in the world I could eat a mango without refrigeration. But the idea that a mango could be like a quasi stable fruit in my house is amazing and great. I think, like, yes, I know they are costs, but like I love mangoes.
Yeah, I think.
One of the sad things that's happened to me as I've researched this book and made my podcast is I've realized how much worse things taste when they are refrigerated.
I mean, but it's not worse than no mango. I'm sure the best mango in the world is amazing, but I love the mangoes that I get.
It depends if you've had the really good mangoes.
Once you've got, then I'm glad that I haven't.
Yeah, there you go.
What's the most surprising detail you learned working on the book?
Oh?
Man, I mean, just because it's the most recent thing we were talking. Came about ice cream. The non premium brands are fifty percent air, and you can't truck them across the country because they'll explode as you go over the rockies. Really, yeah, so the companies have to come up with different formulations for you know, the higher altitude parts of the country, and you can't bring you know, you can't truck your ice cream from your factory in Georgia to sell and Denver is not going to work.
So basically, the as you go up in altitude, the atmospheric pressure declines and the air inside the container expands and blows the lid off.
Yep.
And so when you say non premium, it's like the old school, like pre Hogendaws, pre Ben and Jerry's where you get the big half gallon, not the little pint, Yes exactly. So like hogandaws and Ben and Jerry's are dense enough that you can take those over the rockies.
Yeap, they are less air by you know, volume, and thus you know, yes, they still expand a little, but not enough to blow their lids off, so.
They're not as much more expensive than the cheaper kind once you account for the fact that the cheaper kind has more air.
Yeah, exactly, but some people like the air, you know, it gives a different texture.
Fair.
What's one thing that people refrigerate that they should not refrigerate so much?
I mean, for example, never put stone fruit in your refrigerator. It is the stone fruit killing zone. It literally disables the genetic machinery that makes that the fruit uses to make flavor.
So just don't do it.
Eat the peach or make the peach into a pie. Do not put the peach in the fridge. There's a ton onions and potatoes. Actually, I mean potatoes actually become toxic in the fridge.
Never do that. A lot of people have.
This idea that the fridge is just this miraculous box that keeps everything safe, and that is not the case. It's not the ideal environment for a lot of things things.
What's something that people don't refrigerate that they should h.
Nuts? Us, Yeah, I see as news I can use if you have.
If you don't go through nuts that you're going to go through on a relatively quick basis, Like if you just grab a handful of almonds every day and you go through the bag pretty quickly. Fine, doesn't need to be in the fridge. But if you have, say some pine nuts or some Macadamian nuts that you only use in certain recipes, they will go rancid out of the fridge and they will last longer. I actually keep my Macadamius in the freezer.
Nikki Twilly is the author of the book Frostbite and the host of the podcast Gastropod. Thanks for listening to the show. You can email us at problem at pushkin dot fm. We're going to take a couple weeks off for a summer break, but we'll be back soon. Today's show was edited by Lydia Jane Kott. It was produced by Gabriel Hunter Chang and engineered by Sarah Bruguer. I'm Jacob Goldstein.