Welcome to Stuff to Blow Your Mind, production of iHeartRadio.
Hello, and welcome to Stuff to Blow Your Mind. My name is Joe McCormick. My regular co host, Robert Lamb is out today, so instead I am being joined by a couple of guest hosts, my friends and colleagues, Annie Reese and Lauren Vogel Bomb. Hey, Annie and Lauren, Welcome to Stuff to Blow Your Mind. It's not your first time, but it's great to have you back. How are y'all doing?
Thank you for having us. It is great to be back. And what a topic you have brought for us today.
Yeah. Yeah, I was just thinking the other day about the last time we were on talking about ambergris and how weird that one was.
So yeah, yeah, yeah, delicious squidbeaks, because the weird thing was that we figured out that you can eat ambergris and many people have.
Why not? Why was one weird thingsing whale refuse and turn it into something delicious makes perfect sense?
So would y'all like to talk about Savor and your other projects? Yeah? Where else can people find your work on the internet?
Well? Yeah, A Saver is a podcast about food history and science and culture, and you can find it on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. And I also do a short form science and history show called brain Stuff. Annie does another stuff podcast called Stuff Mom Never Told You, which is a feminist, intersectional kind of kind of gig. Yeah.
Nice, Yeah, book topics.
Yeah. Yeah. We're also about to be on a panel at PRX in Atlanta that is the Podcast Creator Summit. It's happening July thirtieth through August first, And yeah, we're on a panel on the thirtieth called Feeding the Culture taligantlant As Food Stories with a couple of really excellent co panelists and the event is free. There's a free reception afterwards at Monday Night brewing. Come have some snacks and listen to a great time.
Yeah.
Yeah, I'm terrified and excited com hang out.
That's generally how we operate.
But yeah, are you in the same boat as us that? Like, I'm somebody who talks for a living, but I'm kind of scared of doing live events because I'm not good at talking extemporaneously without preparation, and also, like I stumble over my words a lot, And that's why we rely on our wonderful producer JJ to edit out the parts where I say a sentence in a completely mangled way and have to start over.
Yeah, thank you, yes, thank you JJ.
Well, as with the last time you were on the show. Because y'all do such great work with food science and food history on SAVER, I thought it would be a good idea to talk about something food related on Stuff to Blow Your And actually, if everything works out, y'all are going to join me for two episodes of Stuff to Blow Your Mind? Can I can I get you on the on the record committing to that now? Oh wow?
You sure kind of boxing those in.
A corner, but so yeah, Tuesday and Thursday of this week, we're going to do a part one and a part two, uh, discussing the strange and spooky things that can happen to leftovers and other foods during storage. I'm thinking of calling this series food storage mad Science. And this idea was inspired by a specific disturbing food memory I have that still haunts me. Unfortunately I can't remember some of the
key details about it. But can I tell you a campfire story about food and see if y'all have ever had similar experiences?
Please?
Yeah?
Yeah, get out the flashlight. Let's make it spooky.
Okay woo. So once upon a time, I remember this happened when Rachel and I were we're on a little vacation. We were staying at a cabin in the mountains. So good. Actually this is where the slashers happened. Yeah.
Yeah, and Adam in the woods love it.
But the other thing, the other horror here I don't know if y'all can relate, is I'm the cook, the main cook in our house, but I was not cooking with my normal home equipment, and that always causes frustrations for me. I like to be able to use my own pans and utensils and stuff. But so you know, I was using somebody else's equipment, and I made a batch of my baked pasta. I usually do a baked penna.
I think this time it was fusili because I remember the little corkscrew shapes when when the final horror was revealed. But the way before I go on, do y'all do have like a go to baked pasta dishneath it? Are y'all baked pasta people or not?
I'm not generally a baked pasta person. I am a pasta person. Yeah, but I do have a nostalgia for a post Thanksgiving baked pasta. My mom used to make turkey tetrazini, yes, which she would just use shredded turkey, angel hair pasta and cuma mushroom soup. I know there's ways you can kind of like gussie it up. Yeah, that's felicious. We have done an episode on it over on Savor, and it's one of those things that people disagree about how to make it, which is pretty much
everything but that kind of simple savory dish. I have really fond memories of.
Yeah, I'm too lazy to make a baked pasta like pasta all day, but I'm not going to put it in the oven, Like that's an extra step that's way too much.
No going to a second location. No, No, Yeah, I generally do a I do regular pasta more than baked pasta. But when it's a baked pasta, I do like a pinna and a tomato sauce with sausage, roasted mushrooms and spinach, and then I bake that in a casserole with pecorina romano and low moisture mozzarella. Mozzarella melted on top. It's
a jam. It's pretty good. It's sort of inspired by I worked as a as a server in an Italian stant when I was in college, and they had a dish kind of like this, but like without spinach in it. So I've modified it over the years, but that's what I was doing, except this time I'm pretty sure it was the fusille, not the pinny. Anyway, that's not really material. But just wanted to talk baked pasta shop for a second. Yeah, Yeah, So I made this batch of baked pasta, and the
story starts very normally. I baked it, we ate it the first night, and after it cooled off, I covered it up with aluminum foil and I put the leftovers in the fridge. And then a day or two later, I don't remember exactly when it was, I pulled the leftovers out so we could eat some more, and to my horror and disgust, I found the aluminum foil pitted with tiny holes in places where the little pasta corkscrews
had been in contact with the foil. Now the holes were alarming enough, because it almost looked like it had that appearance I associate with food that has been nibbled by like cockroaches or maybe mice, like a little kind of nibbled on eaten by a pest. Look. But then it got even worse because I when I peeled the foil away on the pasta itself, there were these little dots and puddles of residue where what it looked like was that the aluminum foil had melted and left these blue,
gray green polka dots all over our food. Definitely not appetizing. No, at the time, I had no idea what had happened, even though it looked like a form of melting that was obviously not possible. The melting point of aluminum foil is it's very high. It's something like six hundred and sixty degrees celsius or more than twelve hundred degrees fahrenheit. That definitely is not what happened.
Certainly not in a fridge. I would be that you would have greater problems.
You got a Ghostbuster esque issue.
Yeah, exactly.
Yeah, like I'm sorry, goser got into this penny.
Yeah, even the oven. If the castle had been that hot, it would have been obvious for a number of reasons. I think it'd probably be on fire. I haven't done the ignition point of posita, I don't know, but there would be no more moisture left in it, obviously, so there's no way the foil was melting. It kind of looked like it had been nibbled on in a way, but that didn't make any sense because it was stored
inside the refrigerator. So I think at the time, I just assumed this was some sort of weird chemical reaction, but we were in a hurry. I didn't have time to look into it or figure out if it was safe to eat, so I just discarded it moved on, and so I was curious what was happening here. And that's the first thing I want to talk about in our series of weird food storage reactions, because I looked into this and I discovered that my experience here was
not unique. You can find posts on the Internet of people reacting with curiosity and horror to the fact that aluminum oil has apparently dissolved and turned into an aquamarine gun metal stain on their food and the food. Interestingly enough, in the vast majority of these cases, especially where you can find pictures on the internet, is lasagna quite similar to my baked penny. Okay, so I've got some illustrations that I just found on Google Images for you all
to look at here in the outline. What do y'all think you want to dig into that?
No? No, that's gnarly. I don't want no, unless you have used a blue cheese. I don't want my lasagna to be that color. And I'm not Actually I would totally eat a blue cheese lasagna. I was about to no, no, that sounds great, but so no, the answer is no, thank you.
Well, I'm notoriously. I will eat around things. It's not great, but I.
Would do it.
Oh yeah, stray cat mentality. Yeah, just like, oh the food is there? Not going to waste the food. I don't recommend it. It's not a great way to go.
And you know the mold like it's got the little t that go inside right invisible.
Yeah, okay, I can get very creative.
Food daredevil over here. Okay, But so first question, have y'all ever had this experience? Does this happen to you?
I've never seen this before.
Okay, I don't think I've ever I've had aluminum foil get stuck to a dish like little bits of it and just kind of ate around it. But I don't think I've ever had this happen before.
This kind of melting situation, right, yeah.
Yeah, Okay, well then I'll just have to use my experience as the reference point here. But rest assured, it's not just me. This does happen to people all the time. Often it freaks them out and they don't understand what it is, much like me in this scenario. And the question is what is causing this, what's actually happening. In most cases, there seems to be a pretty clear answer, and that answer is something called galvanic corrosion. In the context of food, this has a cute name. It's often
called the lasagna cell. So in crude terms, this is when the wrong combination of storage choices or cooking vessel choices turns a tray of lasagna into a battery.
I feel like lasagna cell. You called it cute, but I'd be nervous. This is a lasagna that's out to get me.
Oh, sleeper cell like a storm or like a like a cell of like spies.
And yeah, yeah, yeah, we are concerned by the way that Annie is herself a sleeper cell. Oh, there's a few words that she pronounces in British English.
Really, what happens when you look at the red queen?
Oh lord, I've never tried.
Getting on my solitaire deck. Uh. Okay, So we're gonna be talking about galvanic corrosion, and I apologize in advance. You know, electrochemistry is not my strong suit. But I really did my homework here, so I worked hard to make sure I'm getting all this right.
Yeah. Anytime people start talking about electrons, I'm like, oh, so you mean a wizard. A wizard is doing something cool. Yeah, but right now I think, yeah, I think we've got this.
I had the same experience. I was like, okay, I really want to understand what happened to my food. I start looking into it. I find a good answer, but then I'm like, oh no, I'm gonna have to remember again what all this stuff is and how batteries work. But it's okay. I think I got a lock on it now.
So.
Galvanic corrosion is also known as by metallic corrosion by metallic as in two metals, and it happens when you've got two different metals arranged in what's called a galvanic cell, also known as a voltaic cell. These two things are basically the same thing, but they're named after Luigi Galvani and Alessandro Volta, respectively. These were two different Italian guys who both set discovered principles in the late eighteenth century
that led to the development of the electric battery. So a galvanic cell is a structure where you've got these two different metals, for example, copper and zinc, and they're electrically connected to each other, so imagine connected by a wire. And then they are also both in contact with an electrolyte solution. So an electrolyte is a substance that can conduct electricity when dissolved in a fluid. For example, table
salt sodium chloride is an electrolyte. When you dissolve table salt in a glass of water, the sodium chloride separates into positively charged sodium ions and negatively charged chloride ions, and then these ions can carry an electrical charge through the water. If the salt water is placed between two different electrical potentials for example, two differently charged pieces of metal,
so salt water can function as an electrolyte. Solution, the galvanic cell is the basic idea that makes a battery work. The simple version of this explanation is that inside a battery, you're going to have two substances. One is called a cathode, one's called an anode, and these will be electrically connected to each other, so like wired together, and then also both in contact with a shared electrolyte solution. Often in
a battery it's going to be a gel. In modern batteries, the cathode and the anode undergo a chemical reaction called a redox reaction, and that's short for reduction oxidation. The anode goes through what's called oxidation, that's where electrons flow away from the anode material, and the cathode undergoes reduction.
This is where electrons flow through the outside circuit into the cathode, and then you also have ions, which are a little charged atoms or molecules, flowing through the electrolyte solution to complete the circuit. This of course creates electrical flow electrical current, which is useful in powering whatever you've got included in the circuit. This is how batteries provide electricity to things, usually by putting a number of these cells in series to create more voltage. And so here's
where we get to the corrosion part. As this redox reaction goes on over time, the material of the anode actually physically degrades and loses mass because electrons are flowing away from the anode. Leftover positively charged ions dissolve out of the mass of the anode and into the electrolyte solution. And when this happens, in a lot of cases, you can see by looking at it that the anode is losing its chemical and physical integrity. It just sort of
bleeds out into the middle. This is not a perfect analogy, but you could look at this physical degradation of the substance of the anode as the fuel that is spent to power the circuit, kind of like how wood is burned in order to power the oxidation reaction that is a fire. This degradation of the anode, when it happens unintentionally between two metals in contact with an electrolyte, that
is what we call galvanic corrosion. There are a lot of common examples of galvanic corrosion in the world that don't have anything to do with food. Galvanic corrosion happens to like screws and other fasteners holding metal in place, so you can think of like steel screws on an aluminum base. Especially. It seems like a lot of the examples happen in the vicinity of the sea, on seaside buildings,
on ships and boats. I know salt does not evaporate with water when water evaporates, but it can be like carried through the air in these little droplets as sea spray. So stuff that's next to the ocean, or even especially sitting in the ocean, but next to it, also it gets the sea spray salty moisture getting all over it and getting in between bimetallic components, and this will end up dissolving the less noble of the two metals over time.
There are other examples too. I think I'm one able to find really good specific examples of this, but I think galvanic corrosion can sometimes happen to jewelry if there are two different metals and enough sweat or if you like wear the jewelry while bathing or swimming, you can end up with a kind of electrolyte water in between them.
You know, salty water, sweat and then maybe if it has i don't know, gold and nickel or you know, two different kinds of metals on it, something can start corroding the less noble of the two metals in the jewelry. And then there are also like really interesting historical anecdotes where they were like consequential cases of galvanic corrosion. Any didn't you dig up one of these?
I did, and I was very, very shocked by it because I was specifically looking for food examples, but I uncovered something I did not know, So yes, non food wise, there is a really interesting history and a long history of scientists and engineers trying to combat galvanic corrosion when it comes to naval ships and even the Statue of Liberty. I learned so much about how to restore the Statue
of Liberty, but I'm going to condense it, Okay. Beginning in the seventeen hundreds, ships in the British Royal Navy started displaying signs of corrosion in the iron nails holding the ships together. Alarmed officials launched an investigation, and they did all these experiments, and they realized that it had something to do with the interaction of the copper sheets inserted in the ships below the waterline of the vessel and the iron nails, causing the sheets of copper to
detach from the wooden holes. Investigation revealed that while some of the nails remained intact, others had almost completely dissolved into this kind of paste. Yeah, the intact nails still had a layer of insulation between the iron and copper, which apparently accidentally was left behind during construction. Like they sure should have taken the insulation off, but they didn't.
But this discovery kickstarted even further experiments with different materials and coatings and how they reacted when exposed to salt water. The British Royal Navy arrived at using a copper zinc alloy, but then okay, jumping ahead. In the nineteen eighties, maintenance workers realized that the Statue of Liberty had been affected by galvanic corrosion. The outer copper layers were separating from
the internal cast iron structure. When the Statue of Liberty was originally constructed in eighteen eighty six, there was this thin layer of shelleck between iron and copper, and it acted as an insulation. Over the years of exposure, to the salt watery atmosphere of Liberty Island and rainfall leaking down from the torch. The sillac broke down, eliminating this layer of insulation, and I apologies I always struggle to pronounce silac. The two metals reacted and the iron started
to rust. To stop this process, the cast iron was replaced with stainless steel, which is resistant to corrosion, and the sillac was replaced with PTFE or tef one. It was a pretty extensive restoration. Oh that's what I'll say.
I apologize if you don't know the answer here, But what was the predicted failure state? Like if they hadn't intervened, what would have happened? Does the statue of Liberty like collapse or does like one part of it come off with the other? Yeah?
Does like her skin just sort of peel off?
Yeah?
So from what I read, it was not a structural issue, like it was not going to be a danger, but it just didn't look great. People were worried about the arms, specifically holding up the torch, but and they did try a lot of interesting experiments to fix that and make the torch a little fencier, like it might actually glow at night. But from what I understand, it was more of a it doesn't.
Look very good issue, Okay, But in the case of like the ships and stuff, this actually was a serious structural issue based on galvanic corrosion, right it.
Was, and that they put those copper sheets in there specifically to combat things that was damaging the wood, like these wood boring worms, I think, and just wear and tear. So it was sort of a new issue. They weren't They weren't sure why it was happening. At first. Those copper sheets made those ships go so much better, like faster, all of that. But ones, yeah, if your whole is falling apart, that's not great. Yeahs are coming out.
Yeah, I don't want my nails to be paste in my ship. That's not a good place for that.
So in a lot of these unintended cases of galvanic corrosion, we're dealing with like natural environmental salt water salt spray as the main electrolyte, but it can be all kinds of things. Lots of natural, common wet organic substances have just the right physical properties to be the electrolyte in
a galvanic cell. In fact, going back to Luigi Galvani, one of Galvani's revolutionary experiments in the eighteenth century was showing that he could make a severed frog's leg twitch with electrical stimulation, which was only possible because animal body parts like a frog's leg, which is food, you know.
Oh yeah, that's tasty.
A frog's leg has moisture and ions like salts that can conduct electricity internal. Another example of a natural, wet, organic substance that works as a perfectly good electrolyte for one of these cells is a potato battery. Y'all made these in school? Yeah, oh yeah, and you play Portal two, Yes, exactly, yeah, so glad ass yeah, which by the end of this episode, I'm definitely thinking of like a Portal three with clad oss as a lasagna, which I think that's got legs.
It does.
So in a potato battery, you stick a like a copper penny and a zinc coated screw into opposite sides of a potato, and then you wire them together, and the wet ion rich interior of the potato facilitates the flow of electrical current, so you can power something like a like a little led, you know, wired between the two metal pieces, though you might need more than one potato and series to power an led because you know, potato battery doesn't put out a lot, but you can
get a little bit of flow. In the case of a potato battery, the anode that is sacrificed that degrades in this redox reaction is the zinc on the screw. It breaks down over time due to galvanic corrosion to supply the electrical current to the circuit. So this brings us back to the lasagna cell like a frog's leg or the inside of a potato. A tray of baked pasta like a lasagna, is usually going to be a wet, salty mass which will facilitate the flow of electrons if
it's positioned as the electrolyte in a galvanic cell. And it is actually quite easy to turn a baked pasta dish into a galvanic cell. All you need to do is have two different metals surrounding and touching the lasagna, for example, a steel pan covered with a bunch of aluminum foil. And this makes a lot of sense. Why is this never happened to me? At home? Home? If I make a baked pasta. I'm always baking in like
an you know, glass or earthenware dish. I think this time, I don't remember exactly, but I think I may have been baking in like a steel or metal tray of some kind.
A lot of less expensive cookware is going to be made of a reactive material like steel or or aluminium. But I think I think you got steel in this case.
Possibly it could be. I'm not one hundred percent on this, but I think it could still be possible to have this with aluminum foil and an aluminum pan if there's like, you know, slight differences in the aluminum there. I'm not sure about that, but I do think it's possible.
Generally speaking, aluminium pans are made not with totally pure aluminum, so yeah, sure.
Anyway, So just think of the example of a steel pan with baked pasta and it covered in aluminum foil. When you do this, the steel functions as the cathode and the aluminum is the an, meaning the aluminium is the metal that's going to break down into grade. You are powering electron flow through this pasta battery and in the process dissolving your aluminium into the wet lasagna below, creating a disgusting mass, a kind of melt movie slime
of aluminium ions piling up on the food. And these ions, I think that there could be all different kinds of aluminum ion or aluminium salt species. I think you get a lot of aluminium hydroxide, probably which is from combining aluminum combining with water. I think this is probably the bulk of the slime. You might also get like aluminium chloride chloride from combining with salt in an acidic tomato sauce. So I think it is very likely that this is what happened to my baked pasta. I made a nasty
melt movie food battery in my fridge. But I do want to add an important caveat, especially because in this series of episodes we're talking about mostly about food storage, like the storage of cold leftovers. For this to work, it didn't need to happen in my fridge or in cold storage. It just happened there because that is where
I covered the pasta with aluminum foil. In fact, I am almost certain this would have happened even faster if I had covered the steel pan with foil and had the foil touching the pasta while it was baking in the oven. Because general adage in chemistry, most things happen faster when it's hot. This is also true of galvanic corrosion. Though hot or cold, the cell still exists and it
will eventually eat the aluminum either way. Sounds so menacing, But Annie, you turned up something interesting, which was that there are examples of this happening, like specifically in hot conditions. I mean, I think a lot of the lasagna examples people talk about are while it's baking in hot conditions, but it also happens in like barbecues scenarios.
Right, Yes, And this is a fun opportunity to use very intense terminology when it comes to barbecue. But another food instance where galvanic corrosion of food can occur is in barbecue when pitmasters use a technique called the Texas crutch.
Oh yeah, oh yeah.
This technique entails wrapping the meat in question, usually beef brisket or pork shoulder, in aluminum foil about halfway through the cook time to prevent what is called the stall are when the cooking of the meat is halted by the evaporation released as it cooks, which cools the meat and stalls the cook time, which in this case is not something you want. The aluminum traps all of that moisture and ideally the drippings to be reabsorbed later while
also keeping the temperature. Even if a steel pan is used, and especially if the marinade contains any tomatoes or vinegar, this process could lead to holes in the aluminum foil and a loss of those precious, precious barbecue juices.
Yeah, so I'm familiar with using a crutch like method myself. One tip that I've picked up I don't remember where I first encountered this is wrapping it in butcher paper instead of foil, and so that helps trap some of the heat and moisture. But yeah, it just seems to come out nicer than when you wrap it in foil. I don't know. The exterior seems a little nicer for
some reason. I'm not sure exactly why that is. I've never noticed galvanic corrosion happening to aluminum foil in a barbecue scenario, but I absolutely understand that it could, and
they were mentioning this in funny shout out. I found it amusing that, like the most comprehensive article I have found about galvanic corrosion in food preparation is not like in a food science journal or something, but it's on this barbecue head website called Amazingribs dot com, which, to be fair, the site looks pretty solid.
I use them as a reference all the time on Clair. They do great work.
Yeah, yeah, thumbs up from what I can tell. Yeah, but yeah, so they say that like if there's the wrong kind of contact or what you're talking about, like a steel pan and the wrong kind of juices or you know, a salty or acidic marinad or maybe I think there could also be issues with just like aluminum foil touching the grill grates. If there's you know, the wrong configuration, you can sometimes get like pitting or corrosion of the aluminum foil around the meat.
Yes, and if you want more details, they've got them. They are very serious about barbecue.
A lot of people are oh yeah, yes, yes, we just did an episode about Memphis style barbecue. It's our first like foray into talking about regional barbecue without having gone to the place and interviewed humans involved with it, and we were.
Anxious some cautions involved yeah.
Oh, yes, people take.
Barbecue traditions seriously.
They do.
We just wanted to be respectful and as correct as possible. Yeah, we did our best. We did our best.
I'm sure we all did great.
I hope so.
Well.
Something else I wanted to bring up here. I've never heard of this, but there is something called oral galvanism. I am not a dentist, but briefly, this refers to a situation where the human mouth produces electric currents due to a variety of chemical factors and interactions between the dental materials used for things like crowns, fillings, or braces and how they interact with saliva and certain types of food.
And this can lead to the accelerated breakdown of these dental materials, and dentists are still looking into this.
By the way, this is interesting. I look into it. Yeah, so you can essentially do the lasagna cell type thing, but in your mouth, with your wet mouth, the saliva, the flesh, the tongue and all that, instead of the baked pasta or the potato and potato battery. Yeah, you can create a flow of electric current in the mouth. And I came across a really good and I thought kind of funny anecdote from history about oral galvanism. This
doesn't have to do with corrosion. This is just about the flow of electricity in the mouth, and the core takeaway is that it is not hard at all to create a simple battery cell inside your mouth with saliva as the electrolyte. There was this eighteenth century Swiss mathematics professor and philosopher named Johann Georg Sulzer who in his philosophy work he was really interested in the concepts of pleasure and esthetics, like the questions what makes something beautiful?
And why is beauty pleasurable? But Sulzer was all so famous for exploring novel dimensions of taste and pleasure with his own body as the test subject. We might call him like a heat of not And the main example I've got here is that he was one of the first people to describe what electrical current tastes like electro gustationian, though he didn't realize that's what it was. He didn't understand. This was before Galvani and volta. He didn't understand what
electrical current was. But he did describe this experience in a paper published in seventeen fifty two in his right. Now, I've got a picture of him for you to look at here. Just look at that little smirk on his face, like he's experiencing pleasure and pain indivisible, I believe.
Yeah, yeah, no, that is a dude who is currently tasting current. I love it.
But in this writing, Solzer describes this experiment where he takes two metals. One is a piece of silver, the other metal. I've seen it widely reported that the other metal was lead, but then other sources said, no, it's not lead. There's silver and another metal. Unclear what the
second one is. And while these two metal plates were touching one another at one end, he took the other ends and pressed them on opposite sides of his tongue, and in between them he tasted something weird, a flavor he described as similar to that of iron vitriol, which is what they used to call iron two sulfate. Why did he already know what iron vitriol tasted like? I'm not sure. I think this guy was probably tasting a
lot of stuff. Yeah, yeah, cool, Yeah, nothing wrong with that. Well, I mean there might be some dangers involved.
But another food dared devil ice exactly, yes, but he noticed that he did not get any of that metallic flavor when he touched either of the two metals to his tongue independently, only when they were both on the.
Tongue at the same time and touching each other at the other end. So the flavor that he tasted was the flavor of his tongue functioning as the electrolyte in the galvanic circuit.
I believe that this is at a modern restaurant somewhere they're doing something like this.
Yeah, what are the You'll probably know a lot better than I do, Like, what are the weirdest, most cutting edge restaurants out of there? What are they doing that's like barely considered food these days?
I don't know, like a lot of foams.
Okay, Yeah, I'm not actually up on it right now, but I do recommend the movie The Menu to anyone who likes horror films and has not seen it yet. It's pretty great.
I actually haven't seen that. I've had it on my list for a while.
Yeah, if you're into watching cooking shows and like in like cooking documentaries, specifically Chef's Table, they got they got like the director of photography for chef's table to come help them on shoot, and it shows it's what it is, wonderful satire. I saw it in a movie theater with the whole row of restaurant industry kids and like we were cackling.
So like beautiful food photography or food cinematography, but also gross.
I wouldn't say gross.
Oh okay, well I just thought my brain went there because of horror.
But yeah, it's mostly.
It's a satire about where they're making fun of the cutting edge.
This is what I had to do, okay to keep astronomy kind of yeah, yeah, yeah, okay, like yes, this is the breadless bread course today. Today we're serving you the idea of bread.
Here's a taco with your greatest secret printed on it. Yeah, things like that.
Yeah okay, but we got to come back to the pasta eating the aluminum foil, my tray of pasta with this like lotus pod trip to phobia trigger pattern of holes in the aluminum. Poking around on the internet, there is another possibility to explain what happened beyond galvanic corrosion.
Some sources out there talking about the corrosion of aluminum foil by food also point to the possibility that acidic foods can dissolve aluminum by a different mechanism than galvanic corrosion, and from what I can tell, this is also true. Acidic foods like tomatoes can indeed dissolve bits of aluminum from cooking and storage vessels and from aluminum foil. And in fact, this is not a new observation or concern.
Fears about tomatoes and other acidic foods, specifically tomatoes dissolving metal containers, both founded and unfounded fears go back for centuries. Right they do?
They do? And so when you've suggested this topic, Joe, it was really interesting to me because through the research that Lauren and I have done on savor, I knew that historically there is a precedent for this, or at least something similar. When tomatoes arrived in Europe from the Americas in the fifteen hundreds, many believed them to be poisonous at first, especially wealthy Europeans. There were a lot of reasons why the leaves and stems are lightly poisonous.
I learned this research just to have my research.
I read recently that you can eat tomato leaves and this blew my mind, and I'm not sure I need to look further into it that this has been like on my list to look into for a couple months now.
Is it one of those things that's a question of dose.
Yes. Basically what I read was like, yeah, it's poisonous, but so is alcohol, Like yeah, okay, like small dosage. Don't take my word for that. Now. That was a very brief research, but I have all believed that they were.
Yes, But anyway, Yes.
Another thing that most relates to what we're talking about to for why people thought tomatoes might be poisonous is that in the seventeen hundreds, these well off Europeans often ate off of these pewter plates that were high in lead content. The high acid levels from the tomato sometimes would cause lead leakage that could result in lead poisoning and even death. Because of this, rich Europeans would keep the tomato as a decoration, poisoned close to them but
not eaten. But yeah, they would not eat them, even going so far as to call them the poison apple. This attitude and belief was also exported to European colonies and colonists with the help of some prominent botanist around the world for many centuries.
Yeah, this was a thing at parties, like these rich humans would just have a table decoration of this thing that they thought was poisonous. Yeah, they were like, what a fun party, guys, look at this poisonous thing. I paid so.
Much money for this poisonous thing to not look at it.
Yeah, I only know the slightest, like headline version of this. But have you all ever talked about is it true that rich people in England used to rent pineapples that they could display at parties.
Yeah, they would carry them around like as a point of interest, but it was too expensive to buy the pineapples, they would rent the pineapple.
Yep.
Perfect.
Rich people got up to some stuff, and I still do and still too. That being said, the poorer classes didn't have this tomato wead problem because they didn't have the fancy lead filled plates, so they were able to eat tomatoes without issue, particularly in Italy, if they could get them anyway, because they weren't widely grown in Europe at the time and they were often very expensive, and not every European country had this hang up. To be clear, I'm pretty sure most of France was like, no, this
is cool. But by the eighteen hundreds, in part thanks to the invention of pizza, the belief that tomatoes were poisonous largely fell away.
There was also one event where this dude like publicly was like, look, y'all, tomatoes are not poisonous and sat on the steps of a church, I believe, and just ate was like, I'm gonna go eat some tomatoes. Come watch me. And a bunch of people showed up, hoping, I guess, to see something grizzly occur. But he just he just ate a bunch of tomatoes and eventually the crowd dispersed.
Wasn't that in the US? That one was in the US?
Oh I'm not sure.
I love I'd love to know what they imagined might happen.
Oh for him to die?
You know, they were to be fair.
This was before Netflix, Like, people had to make their own fun.
So the food deer devil. If food deer devils are devil.
I mean recently someone in New York ate like a ton of cheese puffs and a crowd showed up. So I think these kind of food events attract a certain crowd of.
Folks competitive eating. Hey, yeah, here we are.
This is also more of a fun tidbit, but I just want to throw it in here because it is fun. There was a belief at the time that certain members of the night shade family, like tomatoes, could be used to summon wear wolves. In the sixteen hundred, some botanists argued that the tomatoes should be reclassified in a new
grouping of plants called lycopersicon, which is Greek for wolf peach. So, if you've ever wondered if there was an etymological connection between the lycopene and tomatoes and lycanthropy, there is.
Oh nice lycopene is that the is that like the red compound and the tomato peel.
I believe, so I know it got a big health boost like two decades ago because people were saying it was very healthy and could possibly combat cancer. So lycopine got a real health boost, and I knew it was
in tomatoes. Yeah, well, okay, recently, very recently actually, as of twenty twenty three, some scientists have cast doubt on this lead poisoning caused by tomatoes theory, reasoning that the amount of lead leached from the plates by the tomatoes acidity would have to be quite substantial to ever make
anyone sick. Instead, they suggest it was more likely that people assumed it was poisonous due to its scientific classification and its resemblance to other deadly night shades, because at the time tomatoes were small and they often looked like berries, similar in appearance to the poisonous belladonna. Oh, interesting, it's a lot of classification. Mayhem, to be honest with.
You, I mean, in the nineteenth century, European society was not wanting for causes of lead poisoning.
That's also true. It could have been many things.
In a lot of industrial manufacturing and even just sort of like craft shop scenarios, people were exposed to lead through their work or through products that they consumed. So yeah, there were a lot of ways to get it back in the day.
The interesting thing is there are a lot of accounts of people vomiting profusely after consuming tomatoes, but a lot of it felt more like people saying that was happening unless than it was actually happening. But you can, if you like me love a good horrifying historical quote about tomatoes and how they could kill you, you can find them. But it sounded like it was mostly people being like trying to scare you. I could be wrong. I wasn't there.
But I also this got me thinking because I wonder if there were instances of the tomatoes acid eating away at the integrity of plates or other food vessels and or causing visible corrosion, and maybe that contributing to the fear of tomatoes, because I remember having vague fears when I would notice visible corrosion on some of my cookware plates and being concerned that I was ingesting something I shouldn't be in.
Jes yeah, yeah, doesn't feel good.
Yeah, and that is a real thing. Like, like, the issue is that some materials are reactive to acids and bases both can erode metal surfaces, especially over time and especially when heat is involved, as Joe said earlier, and this can cause anything from like a little weird tint to your food to maybe a metallic taste to your food, to actually bad levels of various metals getting into and
perhaps hanging out in your body. So you know, like very basically, if you can afford to avoid aluminum cook wear, do that. Cast iron is reactive, but not really a worry like like like iron particles are basically fine in your body if you can afford to ruin copper pants
with tomato sauce. I don't think you're worried about any potential health effects that you might be seeing, but yeah, like, like, generally, if you're going to be cooking anything ascitic, like wine or tomatoes, or if you're just boiling lemon juice or sodium bicarbonate, look for non reactive cookwaar like stainless steel or enameled pieces glassware for the oven. Yeah.
Yes, and my goodness, there are a lot of tips out there about what types of pants to use with what ingredients, and there are even whole articles dedicated to acidic items like tomatoes. People do love to fight about it, I'll say, even though there's solid science. But if you're worried about it or curious, there is plenty of information out there. And if you want to learn more about the tomatoes frankly wild history, you can check out Savers
Tomato Reducts episode it is. I had to cut some stuff out of this recap because I was like, this is not actually related, but it's so interesting.
Okay, So savor tomato reducts in the search bar. I'll get people done.
Yeah.
Yeah, it's a good entry point to saver folks.
Oh, it's a fun one. Were Wolves is only the tip of the iceberg.
Okay, So I guess we want to come back to the question of what happened to the pasta in my case and in these other cases on the internet, where you know lasagna is melting people's aluminum oil not melting but dissolving, making these ugly piles of ions. So acidic tomato sauce like you would often find in a lasagna or a baked penna, can sometimes dissolve aluminum, but from everything I've read, this acid metal reaction is typically much slower and results in a lot less aluminum being dissolved
than you would have in the case of galvanic corrosion. However, the fact that acidic tomato sauce is present may actually help speed up the aluminum eating reaction in a galvanic lasagna cell. However, even though this is it's all pretty well established chemistry that you can figure out just by reading, I wanted to see it for myself. I wanted to see if I could create a galvanic corrosion reaction in food on demand. So yesterday I did an experiment. I
started staging an aluminum souer kraut melt movie experiment. So I put out two dishes of sauer kraut on my stovetop. Sauerkraut is I think a good electrolyte, is both salty and acidic. And one of these I put in a steel pan. The other one I put in a ceramic dish.
I covered both of them with aluminum foil, making sure to press down the aluminum foil to the sides of the container so to connect them, have them in contact on the outside, and then also to press down the foil in the middle so that it was firmly touching the sauer kraut. And what happened here, well, I gave it some time, and by God, the results are beautiful. Within just a few hours at room temperature, there was
already a noticeable difference. Ay and Lauren, I have some pictures in the outline for you to look at here. This was this first picture. I don't know how much you can see in that, but I've got another close up down below. So I've got the steel pan on top here and the ceramic pan below, or the ceramic dish below. The ceramic shows no signs of change from the outside, but the steel pan already after just a few hours, has some creepy dark holes and pitting that
you can see in the close up. And then after this in the outline, I've got some more photos from this morning when it had had i guess probably about eighteen hours to go at room temperature. And here you really start seeing the horror. The holes are bigger, they look gnarlier. I mean, they're still not like gigantic, but they look creepy. They look like something that you shouldn't
be eating. And then I've also got a shot of the sauer Kraut below where you can see the dissolved aluminium ions on the top the cabbage as these gray green blue, kind of shiny, dusty looking metallic spots.
Yeah, forbidden glitter. It's beautiful.
Aladd insane in my sour krawt. Yeah, so there was no visible degradation or residue at all on the aluminum covering the sour crowd in the ceramic dish. So in both cases we had the same variable of the electrolyte. In both cases the foil was pressed up against something salty and acidic. Sour krowd again is both, but it only dissolved and eight holes in the aluminum in the
presence of the steel pan. So I think this is further evidence that what happened to my pasta was galvanic corrosion, not just acidic corrosion, though the acidic nature of the tomato sauce may possibly have helped speed it up.
I love that you did an experiment, and this feels like a cold case we're trying to get to the bottom of. Yeah, have really really turned up some convincing evidence right here.
Annie, I want you to be honest. This is your sour kraut. Now, do you eat around this or do you do you? Do you throw it out? You eat around it? Or do you just eat the metal goop?
No?
I eat around it. Okay, I eat around it, but if it tastes terrible, I'll try to keep going, but I might reach a point where I'll stop. Lauren knows, I you actually picked a great topic for me because I do not waste food. Leftovers and how to store them is like my lifeblood.
I also have a stray cat mentality about food, but Annie, Annie takes it to levels.
Yeah, I also hate hate to throw out food. I have like anxiety sometimes when I have like too many leftovers in the fridge at the same time, Like, okay, I want to make sure we get to all these before they go bad.
Oh, Thanksgiving is a stressful time for me, even in terms of leftovers.
But okay, so I guess here we're obliquely addressing the actual question of food safety. Food that has had a bunch of aluminium ions dissolved into it, is it safe to eat. I want to preface this by saying I am not a food safety expert, and I don't want to be taken as giving food safety advice. So the last thing in the world is I want somebody to eat something that they're iffy about because I said it's okay.
Oh yeah, yeah. So none of us here are medical professionals.
Nope.
Essentially, don't listen to anything that we say.
Well, okay, I'll tell you what I've read.
Okay.
So, aluminium hydroxide is generally considered safe to consume in small quantities, at least by like the FDA. Aluminium hydroxide is present in other common foods and drugs. For example, it's present in your stomach whenever you take antacids like maylocks. There's the old brand name of this antacid that maylox
starts with, like mal. I think the MA is for magnesium and the al is for aluminum because it had magnesium and aluminum in it and that was supposed to help counteract you know, the hydrochloric acid in your stomach and settle the stomach. So you know, there are other cases.
Sorry what I never knew that. That's great?
Yeah, So like, yeah, aluminium hydroxide. Again, I'm not an expert, but it generally seems like authorities say that it's nothing much to worry about it. I mean, anything could be poisonous in huge quantities, but in small quantities it's not a major concern. However, there are other aluminium ions and aluminum salts that I don't know. It seem like maybe
not a good idea to consume, like aluminum chloride. I could not find anything saying this is generally considered food safe in any significant quantities, and it seems to me like that compound might be present in these ion slime pools in quantity is greater than you would want to consume.
So again hard for me to say. I'm not an expert, I would personally just still err on the side of not eating that stuff out of an abundance of caution, especially since it's gross anyway, unless you're in a kind of life raft survival situation, why would you need to eat the metallic Milt movie pool.
And I will put in here that when if you're cooking with an aluminum pan and you get a little bit of that leeching effect over time, over years of use, that the danger there isn't the aluminum so much as other metals impurities that could be in the pan, as can frequently happen with very inexpensive cookwaar unfortunately, And so that's more the long term concern about using that kind of cookwaar, not the aluminum itself.
So as far as the food safety authorities go, I think the corrosion of aluminium into food is not considered like a huge cause for concern. But again, like I don't know, I mean, do you do you really have to eat that? Like I would avoid it?
Annie is like, no, I'm morally obligated.
I'm struggling. I'm struggling to get on board with this, but you're correct. I think that's the.
Way to go well, I'm not trying to tell other people what to do. I'm just speaking for myself. However, what I think where I can give advice, I think is if you want to avoid having this problem in the first place and not create a lasagnia sell what are some ways around it. First of all, you could avoid the combination of different metals surrounding your food, so you can bake in like glass, ceramic or stoneware dishes.
If you do have to use a metal baking dish, if you're baking in a steel pan or whatever, you could not cover it in aluminum foil. Or if you must use a metal baking pan or metal storage container and cover it in foil, you just need to make sure that the oil is not touching the food. So if you do those things that they can pretty well avoid turning your food into a simple battery cell, and you can avoid having the robot melt on your cheese.
But if you need power, and you don't have any potatoes about, but you do have a lasagna.
This is a good light small light bulb, a good They did.
The math question how many lasagna batteries would you need to power a city?
Listeners pools right in exactly.
Yeah, this is where we need, we need your your nerd power contact at stuff to blow your mind dot com.
Yes, yes, well I actually have to thank you for helping me solve a food mystery, Joe, because I had not heard of the phenomena of blue garlic or green garlic. Oh yeah, but I once in my food daredevil self ate something that was lined with blue, and all of my it shouldn't have been lined with blue, and all of my friends constantly make fun of me about it, And now I think I know why it happened, and I feel incredibly vindicated.
Oh boy, this is great. So yeah, this was the other I sort of like gave this to you as something to look into because I've had the experience before
of food storage, of storing foods in the fridge. I think specifically, I'm thinking of when I made like a vacuum packed chicken breast that I put like lemon and some herbs and some garlic in there with it, and after some time I noticed the garlic was bright blue, and that's odd, but it connected in my mind to what I'd seen before some home pickling experiments that had some blue or green garlic, and I was wondering what is causing this reaction? What's going on here? Obviously people
might see that in wonder is that kind of thing? Say?
Eat?
I think personally, I just ate it and it was fine. So yeah, fill me in any what's the deal?
Okay, I'm gonna give a very brief rundown of this. It's fascinating, And Lauren please jump in when we get to the fermentation part, because Lauren is our fermentation expert. Over all.
Yeah, I love some bacteria and yeast poop. That's what makes the world go round.
Yes, yes, okay. So another discoloration that might give some people pause is when garlic fermented garlic turns blue or green. This is caused by a chemical reaction between a sulfur containing amino acid aline and the enzyme alinase, and further compounded by either acidic ingredients lacto fermentation are even exposure to heat. Before slicing or cutting, these chemicals remain separated,
but once they're sliced they combine to form allison. This reaction forms pyals, in turn, which are these rings of carbon nitrogen. When these pyrols chain together, they form polypyrols. Polypyrol molecules that imbue the garlic with a green are blue hue, and it's very distinct, by the way, if you've never seen it. If three of these molecules connect, you get blue, while four will give you more of a green color. The flavor pretty much remains the same
from what I read, though perhaps more assertive. I can't really remember and when I ate, what I suspect was this. I don't remember thinking it was strong of garlic, but that's what I read. There really are a lot of factors that go into this whole thing, the age and size of the garlic, the cooking temperature, the acidity. The older garlic is, the more time it has to build up the chemicals needed for this reaction, and the acid helps break down the cellular walls of the garlic and
speed up the whole process. Some speculate that using copper utensils copper rich foods are even copper and plain old water can contribute to this phenomenon, as well as other metals or minerals like iron or aluminium. Just cooking garlic alongside things like onion, which also contain sulfur, or something acidic like lemon juice can turn your garlic blue. This is so interesting to me, but yes, what about blue or green pickled garlic. Well, during the process of lacto fermentation,
bacteria produce lactic acid. When exposed to that lactic acid, over time, the acid interacts with the chemicals in garlic, forms those polypyrols, and the garlic turns green or blue.
It's not a mold.
It is a normal chemical reaction that happens sometimes whether or not the brine is highly acidic yep, perfectly safe to eat. In some cultures and preparations, this blue or green garlic is the desired results. For example, in northern China, blue or green pickled garlic, called Laba garlic is a popular accompaniment to things like dumplings, especially during the cold season and for the Lava Festival, which takes place on
the eighth day of the twelfth lunar month. To make this whole, peeled garlic cloves are aged in a sealed container with vinegar, typically rice vinegar. From what I've read, this results in a more like sweet and sour, pungent garlic flavor.
And so the goal is intentionally to create blue or green garlic that's like what you're going.
For yes, And actually when you and Robert came on our Lunar New Year episode as a crossover, we talked about how a lot of those foods are puns and the history behind them. And this has a long history and a pun behind it that I won't get into, but it's kind of like counting up your money in
the green sort of being your money. Oh okay situation If you are really opposed to your garlic taking on a blue or green hue, though, there are a couple of things you can do, like using younger garlic, keeping your garlic cold until ready to cook, cooking onions and garlic separately, and waiting for the garlic to cook down a bit before adding acid. Some suggest blanching the garlic and using stainless steel products too. There's a lot of tips out there. I've never realized this was apparently a
big problem, but yes, it's safe to eat. So all of this being said, garlic can mold with the tailtale like fuzzy blue and black spots, at which time they should be thrown out. Also, just to note, this is different from purple garlic, which is an entirely separate variety, so lots of lots of garlics out there, lots of colors garlic can take on.
I love it, right, I think I've had purple garlic that that's just like an inherent color in the right.
Yeah, it just grows that way.
Reaction.
Yeah, it's more assertive, is what I read researching this.
So but no reason to be scared of the garlic that turns blue or green during storage. You're cooking, it's moldy.
Unless it's moldy, but you will. There's a clear difference between moldy garlic and what we're talking about with this blue and green garlic. It is a very bright hue. It takes on.
Yeah, in the case of the reaction, not the mold. Yes, yes, well, folks, I don't want to run you off, but we are coming up against our time limit here. It's been so much fun talking de y'all today. Do you want to do another episode with men? Can we do another one?
Yeah?
More weird food science, food storage, mad science, reactions, transformations, explosions.
Yeah, yeah, I think we're in Yeah.
I can't wait. Well, Annie, Lauren, thank you so much for joining me today. It has been a blast. And please remind people again where they can find your work. I know we talked about it at the top, but let's hit them with it again. Repetition doesn't hurt.
Yeah, you can find our podcast saver anywhere you get your podcast. We are also about to be on a panel here in Atlanta at the PRX Podcast Creator Summit. They asked us to come talk about food podcasting, so we were like, sure, that's on July thirtieth. That's a Wednesday from seven to nine pm. It is free, open to the public, located at the Plywood, So come on out if you're interested. They've got a bunch of other really fascinating sounding like if you are into audio creation.
The whole thirtieth to the first is a bunch of workshops with a bunch of really cool humans just trying to make podcasting more accessible to everyone.
So yeah, and also, Lauren, people can find your work on brain Stuff the podcast and any people can find your work on stuff Mom never told you correct?
Yeah?
Anything else? Before we close out, go.
Listen to our Tomato episode.
Okay to it. That's your homework. That's your homework, listeners, Yeah, savor Tomato redocs. Yes, okay, let's see. Hey, if you're new to the show today. I normally co host this with a guy named Robert Lamb. He'll be back with me, I believe next week or maybe later this week, but generally. Stuff to Blow Your Mind is a science and culture podcast with core episodes that publish on Tuesdays and Thursdays
of every week. On Fridays, Rob and I usually do a different kind of episode called Weird House Cinema, where we just talk about weird movies. They can be good, they can be bad, they can be old, they can be new, they can be well known or obscure. The only real criterion is they got to be weird. Let's see. We also do short form episodes on Wednesdays, and then on Saturdays and Mondays we run some episodes from the vault, older episodes of Stuff to Blow Your Mind and Weird
House Cinema. If you want to find us on social media, I think we're on some of those things. I don't know, I'm not attached to that world, but you can definitely find on like Instagram, and Weird House Cinema has a profile on letterboxed dot com. That's a social kind of film website that it has reviews and film lists and stuff like that, I think we're just called weird house on Letterbox. Huge thanks, of course too, Annie Reese and Lauren Vogelbaum for joining me today, And huge thanks as
always to our excellent audio producer, Jjpozway. If you would like to get in touch with us with feedback on this episode or an together to suggest a topic for the future, to tell us how many lasagna batteries it's going to take to power a city, or anything else, you can email us at contact at stuff to Blow your Mind dot com.
Stuff to Blow Your Mind is production of iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you're listening to your favorite shows.