What happens to coffee when it cools down?
Hey. I'm Melissa.
Jam:I'm Jam.
Melissa:And I'm a chemist.
Jam:And I'm not.
Melissa:And welcome to chemistry for your life.
Jam:The podcast helps you understand the chemistry Happy everyday life.
Melissa:Okay, Jim. I'm really excited about today's episode, but it's also a little bit Off the cuff, maybe, is a good way to put it.
Jam:Interesting. I was gonna I was trying before you actually said what you're gonna say. It's a little bit. I was like, what could it be? What's a word she's gonna say?
Jam:I was my hypothesis in those milliseconds was Scary that you're gonna say it's a little bit scary.
Melissa:It is kind of scary, actually, because I feel like I didn't get as definitive of an answer as I wanted. And sometimes that's scary to come even as a chemist with a PhD, I really am committed to giving good information. And Sometimes I get scared that maybe it's not not the best information, or should I just wait on this until there's more information? But I decided to just bring y'all along with me Nice. Because it's an interesting topic.
Jam:Okay. Cool. So it's back like, here's an interesting question. Here's what we can find out about it right now.
Melissa:Yes. Okay. Exactly. So or what I can find out about it right now.
Jam:Right.
Melissa:So today's episode is about what happens to hot coffee when it cools down.
Jam:Oh. And it's in
Melissa:spiral and spiraled. That's
Jam:so viral.
Melissa:It's inspired by a viral TikTok where a coffee roaster is trying to explain that. Like, he, girl asked why does cold brewed coffee taste good or iced coffee taste good, but hot coffee tastes bad when it cools down.
Jam:Okay. Okay. Yeah.
Melissa:And so he does a thing called stitching, where, basically, you just respond to it, and he explains it.
Jam:And by the way, guys, she's explaining the TikToks that for my benefit. Y'all fire, like, we know how it works. Okay.
Melissa:Right. Jam doesn't know how it works. I don't
Jam:know how it works.
Melissa:Jam's not on the The TikTok, which is honestly a blessing, because TikTok's kind of a time suck.
Jam:And I heard it's on the phone, the, this phone screens?
Melissa:Yeah. It's on the phone screens. Yeah. So that's where I found it on my little phone screen box.
Jam:I kept meaning to look into those. I've heard that they're really cool.
Melissa:Stop. He does have a phone.
Jam:I'd be like, how is he, On one hand, like, producing this podcast and, like, editing it and all that stuff. And on the other hand, doesn't even know what a phone is.
Melissa:It's like Sometimes I do think I'm just gonna get phone and let it simplify my life a little.
Jam:I have considered that too. My younger brother did that for a while.
Melissa:Did he like it?
Jam:He did, and he goes back to it frequently. Like, I mean, Depends kind of the season. Just have her he'll be like, man, I gotta go back to my dumb phone. Yeah. But and so I never know.
Jam:I text him. I I don't know until The bubble either turns blue or green
Melissa:when it makes it. That's great.
Jam:And then it's like, oh, okay. It's back to dumb phone.
Melissa:But Okay. So What this coffee roaster said about why hot coffee tastes bad when it cools down is what he said was essentially there are these molecules called lactones, and they break down into acids. And he says a few other things about, like, the way our taste buds react to different temperatures. Mhmm. But I heard the part about the lactones breaking down into acids.
Melissa:And At first, I was like, that makes sense. That is a reaction that happens. And then I thought but I'm not sure what happened in those conditions.
Jam:Okay.
Melissa:So I truly spent hours researching this because I couldn't find anywhere in the coffee chemistry or food science world Anyone who said the same thing that he said. And the problem is there's a lot of chemistry that looks into different roast temperatures Mhmm. But not the different temperatures of the coffee itself. You know, if we roast it this way, what compounds are present? If we roast it this way, what compounds are present?
Melissa:Mhmm. There was a lot of that, But there was not a lot of same roasting, same brewing method. Let's watch it as it cools down. There wasn't a lot of that.
Jam:So I actually have seen, a study that was done. It's kinda funny that, like, obviously, once you go into the realm of coffee, there's Yeah.
Melissa:A chance
Jam:that I would see this kind of stuff Where it wasn't quite what you're talking about, but it was this the idea of the sensory experience for
Melissa:Yes.
Jam:Coffee drinkers And what the experience is like and why it's different depending on how the coffee is brewed or what temperature is being drank.
Melissa:Yes.
Jam:So cold brew or iced coffee, Those different ways of doing that versus hot coffee that's cooled down, and, in one of the several, like, different coffee newsletters I Received? Yes. I saw something about that, which it sounds like it's in a similar thing, but not quite the question you're Yes. So, I think I saw that
Melissa:same one where it's like hot brew versus cold brew kind of thing. Yes. Yes. So there was a lot on that I could find, like, hot brew versus cold brew. And then, also, we can talk about this more at the end.
Melissa:But to a degree, the temperature can affect your sensory experiences. So just like
Jam:Yeah.
Melissa:Literally, your taste buds function differently at different temperatures.
Jam:Yeah.
Melissa:We could talk about that later too. But what those articles looked at was more how the sensory experience changed and not why Right. Really.
Jam:Right.
Melissa:Or they there were some that looked at why they were different, you know, the chemistry difference at the molecular level between hot brew and cold brew. But it what was specifically hard to find and what specifically I was looking for was hot coffee that had cooled down.
Jam:What has happened At the molecular level between those 2 coffees.
Melissa:Right. Yeah. What's going on at the molecular level?
Jam:Got it.
Melissa:And what's hard is When I tried to look this up, what I found was a bunch of articles that were not science articles, like magazine type articles, or I don't know what they're called when they're on the Internet.
Jam:Yeah.
Melissa:But that type, you know, like USA Today or whatever
Jam:Yeah.
Melissa:Quoting the TikTok that I had originally found that I didn't really trust, that I wasn't sure about.
Jam:Right.
Melissa:So I liked. I wanted to share that because I do think it shows how how easily a little bit of misinformation can spread. Yeah. Know, he shared okay. This is what he didn't say think.
Melissa:He was like, this is what happens. And then I thought, I'm not sure, so I'm gonna go look that up. And it was really hard to find
Jam:Yeah.
Melissa:Anything other than the, like, the first layer of the Internet was just people quoting him.
Jam:Interesting.
Melissa:Yeah. So it this is 1 episode that I probably spent maybe 4 hours researching for.
Jam:Yeah. Dang.
Melissa:I went down a rabbit hole trying to really find what I was looking for. 4 hours maybe researching and pulling everything together.
Jam:Wow.
Melissa:So What he said is lactones breakdown into acids, and he said into, you know, 2 different types of acids. And that's Almost true. Really, lactones and acids will switch back and forth between each other. Mhmm. It's the idea of an equilibrium.
Melissa:We talked about that idea more in-depth on our fluoride episode, if you remember.
Jam:K. Sounds familiar?
Melissa:Yeah. And lactones are just that that's actually sort of a functional group. It's a cyclical compound. It's a ring. Okay.
Melissa:They call it a cycle or a cyclic Compound. So it can basically open up into, like, a straight chain. And that straight chain gets some Protons added to it, and it's called an acid. So, basically, it could be closed into the ring. That's a lactone.
Melissa:Open out in a ring, add some protons. There's an acid. And they that reaction this is interesting because it's reacting with itself to make the ring, to open and close it. We haven't talked about The fact that that can happen, really. But Uh-huh.
Melissa:Molecules can react with themselves to become rings.
Jam:Interesting.
Melissa:But in this case, You know, it's sort of like the ring closes and the ring opens up and that exists in equilibrium. So some of the molecules are closing. Some of the molecules are opening. It's sort of going back and forth until there's roughly an even rate of opening and closing, happening back and forth.
Jam:Okay.
Melissa:So for more details on that equilibrium, go back and give that fluoride episode a listen. But you can sort of control the If you want more of one thing or the other, if you want more of the ring versus more of the open one, you can change conditions. And the thing that confused me a little bit about what he was saying is that in acidic conditions, Actually, I think the lactone is favored over the open chain acid.
Jam:Okay.
Melissa:Is The reason I I sort of think of it, although this isn't exactly accurate, I'm like, oh, yeah. Well, if it's acidic, there's already asked like, in acidic conditions, there's already acid. It doesn't want more acid, so it'll just close-up.
Jam:Right. I see.
Melissa:It was hard to find in the specific conditions of coffee if that was true. But that's what gave me a little red flag. So that was my initial I'm not sure if this is happening. You know? Yeah.
Melissa:And so I had to dive deep, like I said, And I couldn't find anything specific that lined up with this idea that lactones break down into acids and make our coffee taste Sour.
Jam:Mhmm.
Melissa:But what I did find in food science articles was actually the opposite. So in all the food chemistry articles I could find, actually, most people agreed that the progression goes from the acid to the lactone. So from the open chain to a closed chain. And actually, the acid is kind of sour, but the closed Chain, it's a specific type of acid. Chloric acid, and then it becomes chlorogenic acid lactone is what it's called.
Melissa:If you've ever heard those terms in the coffee world. The lactone gives this nice bitter flavor that's, like, unenjoyable a little bit. Uh-huh. A good bitter They is what they called it, but then that can break down even further into something that is a bad bitter flavor.
Jam:Okay.
Melissa:So that's what all of the science articles I could find said is that He's so close because he's sort of just talking about how, basically, as it sits out, chemical reactions happen. And This is the one that happens, and that's why our coffee is sour is because there's more acid present after it cools down. It is true to a degree that as your coffee sits out, chemistry is happening, but it's kind of happening in the opposite direction he talked about. Yeah. And the acid acids aren't usually considered to be bitter.
Melissa:Acids are more considered to be Sour. Right. There's like I don't know who started tasting things, you know? Yeah. But Yeah.
Melissa:There's a thing that, you can remember, like, for acids and bases. And the bases taste bitter, and they turn This paper that checks for a city or base city's deep blue. So basic is a bigger pH. It's Bitter, and it turns the paper blue. And all that starts with b.
Melissa:Right. So when he said, you know, like, oh, I think it's more bitter. I I think that's part of the thing that I was like, room temperature coffee is more bitter. That shouldn't be more acidic. So I was kinda confused.
Jam:Oh, I see.
Melissa:Yep. That was just part of what that was on the side. That was what Kinda put me off originally.
Jam:Yeah.
Melissa:So then I was like, well, What's the thing it breaks down into, and how does that happen, and why does it happen more with hot coffee than, like, cold brew coffee?
Jam:Yeah.
Melissa:You know, all these questions started swirling around in my mind. Well, guess what? That was even harder to find. But I did find 1. It was a lecture.
Melissa:It was a recorded lecture. It was not a peer reviewed journal article, but it was a lecture recorded with A food chemist who studies coffee.
Jam:K.
Melissa:And he couldn't share the exact mechanism due to, copyright and binding issues, but he alluded to the idea of a radical reaction. I think we've talked about radical reactions some. But do you remember much about it?
Jam:No. I mean, how how related is radical reaction to just radicals, period?
Melissa:Very, very related.
Jam:Okay. Okay. Is it that something ends up being left with fewer electrons than it Wants or needs or something?
Melissa:It's that's really close. So a radical is an unpaired electron. Electrons like to be paired up.
Jam:Right. And they
Melissa:kind of counterbalance each other out, so they're much more stable when they come in twos.
Jam:Okay.
Melissa:Like, the ants go marching 2 by 2. Right. You know?
Jam:Right. Yeah.
Melissa:Right. Yeah. Definitely. So but if there's only 1 electron, then it starts wreaking havoc.
Jam:Right.
Melissa:Also why it's called a radical.
Jam:Yeah.
Melissa:And we talked about that in our Benzoyl Peroxide episode, and I think a few others like the antioxidant episode. Radical reactions work in 3 steps. They call it initiation, propagation, and termination.
Jam:Okay.
Melissa:So the initiation step, a radical is formed usually by heat or light. K. The propagation step is really, I think, what makes radical so interesting. I feel like maybe we've talked about this on the podcast before, but I also teach it in class. So it's very hard for me to know if I'm, like, having deja vu because I taught it in class or because I've taught you it before.
Melissa:But the propagation step is where The radical will go find a nonradical molecule, and it will scavenge sort of. It'll steal an electron and make a bond with that. Yeah. So imagine I'm a radical. I have 1 electron.
Melissa:And you're a bond, and you have 2 electrons. Uh-huh. That's what a bond is. It's, you know, 2 electrons being shared usually.
Jam:Yeah.
Melissa:So I'll steal one of them. And that means now I'm stable, and I'm not a radical anymore, but now you are radical.
Jam:Right. Right.
Melissa:And so that's why it's called propagation. It's propagating itself. It's continuing to make more radicals as it reacts.
Jam:Right.
Melissa:And then termination is when 2 radicals find each other. But unless we're in really Controlled conditions where there are is a high number of radicals to nonradical species, Termination is less likely. You're a lot more likely to come into contact with a regular old molecule than with a radical reaction. Okay. Okay.
Melissa:So the way I kind of thought of it was like a domino effect. You know? Like, you have a radical, and That makes another radical, and that makes another radical, and that makes another radical, and that makes another radical. So, like, sort of, like, as the dominoes fall?
Jam:Yeah.
Melissa:So that's a radical reaction.
Jam:Okay. Okay.
Melissa:They tend to keep going unless they're in conditions that that are designed to go for a certain amount of time and make them stop. And they use radical reactions to make plastics actually and some other polymers, So they can be very useful, but they just I would say they're a little difficult to control.
Jam:Okay.
Melissa:So as I mentioned, it Turns out that the lactones are formed from the acid, and then they break down further into something grosser and bitter in a bad way Called Phenylindanes?
Jam:Mhmm.
Melissa:Have you heard of that in the coffee world?
Jam:Uh-uh. Or if I have, then I didn't remember it. But
Melissa:Okay. It doesn't really matter. It's just another class of molecules, but they're more bitter than even the in a bad way than the lactones and the acid.
Jam:Okay.
Melissa:And these phenylindanes seem to be maybe a newer realization. Like, in the last 10 to 15 years, did they say, like, Ophenylindanes appear to be what's making coffee really bitter.
Jam:Okay. It
Melissa:it was hard to get information about these, but I found that lecture with a food chemist. I believe it was doctor Sarah Marquart Marquart. I'm not sure how to pronounce it, but she had a lecture where she was talking about her research. It was, like, at a coffee conference. Uh-huh.
Melissa:So that was kind of cool to find. And she mentioned that she's been studying these phenylindines, and she proposed that They may be formed by a radical reaction.
Jam:K.
Melissa:And that was the most I could find. So I'm trying to be very transparent about the fact that this was not a peer reviewed journal article, but it was from a scientist who studies this.
Jam:Got it. Got it.
Melissa:So I feel it's a trustworthy source. If I find out if more information comes out and that's not right, that's fine. But I wanted to bring you along with this chaotic journey with me. So What's significant about the fact that it might go by a radical reaction to make these bitterest compounds is that radical reactions keep going. So if the radical reaction is initiated by heat in the roasting process, That is possibly why roasting for too long makes coffee more bitter.
Jam:Right.
Melissa:Because there's more Time for radical reactions, more initiation of radical reactions, and more time for them to propagate so you get more of these phenylindates.
Jam:Okay.
Melissa:Then if you think about the way, you know, molecules work after the roasting process, they'll kinda calm down. They're in the bean. There's they're not there's not a lot of Opportunities for the molecules to interact. So reactions don't usually happen as much if you just have, like, a solid state of something sitting out.
Jam:Right.
Melissa:Because It's just at room temperature, so there's not a lot of energy put into it to move around. But also, it doesn't have a medium to move around in.
Jam:Right.
Melissa:You know? It's like just solid. It's not can't come into contact with other things very easily.
Jam:Right.
Melissa:So There's less reaction than when your coffee is sitting on the shelf. But if you then Brew that coffee by a hot brew method. In my mind, this is totally chemistry off the cuff. But in my my mind, what I could what will happen is when you put something in liquid, in a solvent of some kind, and you heat it up, You're adding energy in for the molecules to move around more. You have heat to initiate a radical reaction again, and There's this medium that they're gonna interact in.
Melissa:More heat, molecules are moving around more, so you have heat to initiate the reaction, heat to Let the molecules move around more and a medium for the molecules to move around in, which to me made me immediately think, oh, that radical reaction is gonna get going again.
Jam:Right. Right.
Melissa:So if we hot brew our coffee and the radical reaction gets going again, then more and more of these bitter compounds are forming.
Jam:Got it.
Melissa:And even, you know, if it's not hot for very long, that's different than if you have a cold brew method.
Jam:Right. Right.
Melissa:Because you'll have a medium for them to move around in, but you're not initiating more because there's not heat.
Jam:Right.
Melissa:And you're not helping the molecules move around faster because there's not heat. In fact, you're making the molecules move around more slowly if you have a cold brew coffee.
Jam:Totally.
Melissa:So I was like, oh, wait. This really makes sense. And then this is where the second thing that comes into play, the what you were talking about, That our taste buds actually function differently at different temperatures, where above a certain temperature, we can't taste as well, literally. We can't taste as many things.
Jam:Yes.
Melissa:And so it's possible that there is a dual action thing happening where we're getting more radical reaction in our hot brewed coffee
Jam:Mhmm.
Melissa:That is going to make more of these bitter molecules. And then at the same time, as it cools down, it goes into the range where you can taste those bitter molecules really well.
Jam:Right. And the the Being able to taste different temperatures is something that plays into coffee a lot. Yeah. Where where you like cuppings of new coffees and stuff like that.
Melissa:Mhmm.
Jam:They They say, you know, yeah, go ahead and taste it as soon as you can kinda handle the temperature, but make sure you're continuing to taste it as it cools a bit. Mhmm. You're actually getting a good idea of what the coffee tastes like. None of us drink our entire cup of coffee while it's
Melissa:Right.
Jam:You know, a 100
Melissa:and Except jam.
Jam:30, 40 degrees.
Melissa:Who has that fancy cup that keeps it warm?
Jam:That's true. But even then, it still kinda changes, which It's probably good reasons for that. But
Melissa:probably the reaction continuing to go.
Jam:But we talk about that all the time in terms of, like, you're not really getting a good idea of the coffee if you're only tasting it at one temperature.
Melissa:Right.
Jam:Because it's constantly changing. But they also often say that the thing about it being that hot is it's also probably the beginning is probably the worst one of the worst times to actually be able to tell
Melissa:Right.
Jam:What the coffee really tastes like because our taste buds just can't do it. Mhmm. And so, like, a few minutes later is is much better. And those things are still there. It's just that we weren't able to taste them
Melissa:Right.
Jam:Or whatever. That plays into that world a lot. So at least that part Seems like something that the coffee world has understood and gotten
Melissa:Mhmm.
Jam:That part right so far.
Melissa:And he did talk about that in the TikTok. And I really the reason why I'm not referencing the exact one is I don't I don't want this guy to feel bad. I think he I think he probably He's a, I think, a coffee roaster by trade, and so that part of the information was correct. And also the idea that as it's sitting out, it's reacting, that's correct too. But I was like, Nobody cares about the exact reaction except for me and my small community of chemist, but that's not right.
Jam:Yeah. Yeah. Yeah. Totally.
Melissa:Or I guess the better thing is that doesn't seem right. What I think is It's so close, but Yeah. Something doesn't quite fit. And so I just wanted to dive into that and try to find the best information that I could about it.
Jam:Totally. Totally.
Melissa:I oh, and I just realized since I was talking about that that I didn't that I didn't give credit where credit was due. I recently did a lecture in at Baylor University.
Jam:Uh-huh.
Melissa:I have a colleague who works there. She's really nice, doctor Harridge. And while I was there, a student asked this question and told me about this, this TikTok, which is what made me go listen. And at first, The guy I was, like, oh, yeah. That totally makes sense.
Melissa:And then the more I thought about it, the more I was, like, wait, hang on. Yeah. I have some questions about this. So I wanted to shout out that student, Allison s. She was really excited about it, and I think she even did a project for class about the coffee episodes that we did.
Jam:So Nice.
Melissa:She's she was really nice, and I wanted to shout her out because I would never have found this without her asking that question. So I really appreciated that.
Jam:That's awesome.
Melissa:Anyway, back to what I was saying. So, yeah, I think that He was really close. It was it was close information to have, but I just wanted to take it a step further and dive into this question With all of this science community here. Yeah. The other thing I wanted to say was I can see that cold brew coffee iced and cold brew coffee wouldn't have the same Bitter as it cools down thing happening for two reasons.
Melissa:One, I already mentioned, cold brew coffee won't get the heat into it. Yeah.
Jam:In the 1st place.
Melissa:Right. So I think that the reaction is just happening slower with cold brew coffee, honestly. It's probably happening as soon as the you have the water added, and so the medium, You know, is getting the molecules are able to move around a little bit more. Right. And they're able to interact a little bit more, But it's cold, so it's like they're you're taking heat out of it.
Melissa:So the they're moving less than they would in a hot situation. So that's why I think it lasts longer
Jam:Right.
Melissa:In the fridge.
Jam:Right.
Melissa:And you're not getting that 2nd heating where the initiation step happens.
Jam:Okay.
Melissa:And there is evidence to back up that Cold brew coffee and hot brew coffee have very different molecules present. So that's interesting. Yeah. With iced coffee, which is hot coffee brewed onto a cold setting.
Jam:Right. So it's immediately being cooled down.
Melissa:Yep. That immediately slows down the reaction, but also both of those coffees are served on ice, which takes our taste buds to the other end of the spectrum also lessening our ability
Jam:to taste. Right. Right.
Melissa:So that's my suspicion is, like, well, it being cold, you're taking energy out. Mhmm. And that means the molecules are moving less. Reactions go slower when they're colder. Mhmm.
Melissa:I get I mean, I can't I can't think of a time where that's not true. But maybe in general Yeah. If you have less energy, the molecules are moving less, so the reactions aren't able to move like, the molecules aren't moving around as much. The reactions aren't able to happen as effectively. Mhmm.
Melissa:But also, it comes into play again with our biology that our taste buds, When it's cold, they are also a little bit less effective just like when it's hot.
Jam:K.
Melissa:So I think those are the 2 things that make it to where iced Coffee and cold brew coffee don't have the same extent of the this is bitter as it cools down Experience.
Jam:Interesting.
Melissa:Isn't that?
Jam:Yeah. That's crazy. There's so much there.
Melissa:I know. And I I did also wanna say, This is the it's probably even more complex than I'm making it.
Jam:Right.
Melissa:You know? I I tried to boil it down to something that was I was pretty confident that it was accurate based on the sources I had and something that was a teachable chemistry lesson. But there's So many molecules that make up coffee, and there's so many reactions that are probably happening in addition to this one. Mhmm. And we Haven't even fully elucidated this reaction mechanism.
Melissa:So that's why I said it's a little bit of chemistry off the cuff, and It's definitely simplified down. Yeah. But I think this is a good informed idea of what's actually happening when our coffee cools down.
Jam:Right. Right.
Melissa:So yeah. Isn't that fun?
Jam:Yeah. That's crazy.
Melissa:I had a great time. I love a good challenge, and I got really motivated to to do this one. So I really, really enjoyed this a lot.
Jam:Yeah. And I definitely wondered this myself. I am committed. I always finish drinking the cup of coffee even if it's getting cool. But I also I'm starting in a much better place where I'm getting the some of the best coffee I can get my hands on, Which means that even though, yeah, it does taste a little less good when it's gotten down to room temperature something, it doesn't turn bad.
Jam:It doesn't turn light. Yeah. I have had coffee, like, say gas station coffee from my side. Yeah. Just as an example.
Jam:Sorry, gas stations. But, it's actually kinda better when it's really hot, and you can't taste it as well. Mhmm. And then the cooler it gets, the better the more you're tasting it. And it's actually, in that case, a bad thing.
Melissa:Yes. Some coffees actually, They have different compounds. You know, there's so much to the variety and origin and stuff that they taste better when they're a little bit cooled down. It's like some of the stuff I was reading, but That was beyond the scope of this episode, so I left it. But I also had had the thought that even though the reaction slows way down when you put it in its solid state, It's probably still happening.
Jam:Yeah.
Melissa:So if you freshly roast your coffee and then consume it rapidly after that, which you do Yeah. You're much more likely to have less of the radical reactions happening on the shelf. Right.
Jam:Right.
Melissa:You know? So the faster you consume it, the less it goes, quote, unquote, bad by making more of these Bitter taste molecules. But, also, it seems like there's a little bit of evidence that the bitter molecules Might be part of what has a good antioxidant effect, but I didn't get into that because I was like, nope. Nope. That's another episode.
Melissa:Yeah. So but they thought the fennelindines might be part of what makes coffee actually kinda good for your health.
Jam:Interesting.
Melissa:I know. But then I was like, no. No. No. No.
Melissa:No. We can't We can't I can't tell you how many tabs I had open, like, trying to get get information. I ended up using, I think, like, 15 sources. Let me count.
Jam:Oh my gosh.
Melissa:Seventeen sources I ended up using for this, and I had more than that. But I tried to distill it down only to the ones that actually informed Exactly what I was doing.
Jam:Right. Right.
Melissa:So so yeah. Do you wanna take a stab at telling it back to me?
Jam:Sure. Okay. So when we brew a cup of coffee
Melissa:Yep.
Jam:It's super hot at the beginning.
Melissa:Mhmm.
Jam:But and when that happened, when we were brewing the coffee, There's lots of energy there. There's lots of things we've just done.
Melissa:Mhmm.
Jam:And this radical reaction has started at that point. Correct?
Melissa:It starts when you roast it.
Jam:When you're roasting, but then we've sort of
Melissa:Then it kinda slows down.
Jam:Slowed down because the beans are at room temp Hanging out in a cupboard.
Melissa:Yeah. So it might still be happening. I mean, I think it's likely that it's still happening in a Yeah. Slow way.
Jam:We've ramped it up a bunch By introducing a bunch of heat and getting a medium for everything to be moved around in. Correct?
Melissa:Yes. I mean, most chemistry reactions that I do Yeah. We put it on heat. Right. A lot of them.
Melissa:Like, in the lab, we heat them up. There's a few exceptions, but
Jam:Let's just say, the heat's on.
Melissa:Right? Heat's on.
Jam:Heat is on. And we've we're brewing this coffee. The heat is ramping up this radical reaction.
Melissa:Mhmm.
Jam:And so a bunch of these radicals, these electrons are bouncing around, and they're starting sort of chain reactions everywhere they go. Right?
Melissa:Yeah. So, when I think of it, it's like A molecule that for some reason has, like, one little wayward radical, like, one little wayward electron that doesn't have a buddy. And so anywhere it goes, whatever it interacts with, it's gonna steal an electron from that and then make another one of itself and steal a reaction from that and make another one of itself. So it's like converting as it goes. I mean, we don't know the whole mechanism, but converting as it goes, lactones into these other things.
Jam:Okay. So it's doing that. So when we first drink it a cup of coffee Mhmm. At the temperature we can start drinking it at. We're mostly in terms of flavors, like that, we're tasting there's good amount of acids there.
Jam:It's this sour, not quite bitter Depending on the way you wanna use those words, but, like, that might be the a slightly more accurate way to put it.
Melissa:So what I my understanding was is that There's chlorogenic acids that during the roasting process Mhmm. Change into lactones.
Jam:Mhmm.
Melissa:I think there's still chlorogenic acids there.
Jam:Right.
Melissa:But they there's a lot of lactones too.
Jam:Uh-huh.
Melissa:And even in the roasting process, you can start to get some of the phenyleneda. And so it's like, The acids are the kinda sour. They're most present when the coffee is green. Mhmm. And then This is my understanding.
Melissa:And then as it roast, there's more of the lactones present. And then as it goes beyond The peak roasting time
Jam:Mhmm.
Melissa:Further roasting or brewing, that's when more of the conversion From the lactones to the phenylindane happens. That was my understanding.
Jam:So, basically, our cup of coffee already has are all 3 there.
Melissa:Yes. That was what I that was my understanding.
Jam:But as the coffee goes from hot to cool, and as more radicals are bouncing around And cause more chain reaction and stuff like that. The so that sort of ratio, you could say Yeah. Is continually changing.
Melissa:Yep.
Jam:Fewer acids more acids are turning into lactones.
Melissa:Yep.
Jam:And then lactones turning into phenylenedene?
Melissa:Yeah. I hope that's how it's pronounced. I could've been saying it wrong this whole time.
Jam:It reminds me of this scene in the movie Fletch, which is like a old eighties comedy with Chevy Chase that my family's watched ever since I was a kid, Where he is often trying to pretend to be somebody else so he can just give information. He's a investigative journalist. But sometimes he just is not on, on his toes as well as it should be. And so one of the times he calls somebody, he's trying to pretend to be somebody to get some information. And they're like, I'm sorry.
Jam:And who are you? He goes, oh, this is mister Phenylindanes makes me think of that. Sinalindenden.
Melissa:It could be phenylindanes, not phenylindanes. Like, maybe I'm hitting the l too hard. Mhmm. But that's, like, roughly how it's spelled. So
Jam:Right.
Melissa:You know, coffee community, come at me, correct me, and I'll be fine.
Jam:I mean, Sounds like you're coming at them at them. So just kidding.
Melissa:Yeah. That that's true. I really I feel bad. I've never made such a direct No.
Jam:No. No. I I'm just kidding. I think it's perfect. I think it's great.
Jam:I so the Those things are happening.
Melissa:Yeah.
Jam:They've already actually really started in the grocery grocery process. But
Melissa:Yes.
Jam:Once we've got our cup of coffee and it's cooling, the The amounts that were are in there at the molecular level of acids to lactones to phenylindanes Mhmm. That is slowly changing, While the cup cup of coffee is just sitting there?
Melissa:Yes.
Jam:And that would mean, so you take a sip right at the beginning, and then you walk away And forget your cup of coffee, which, you know, even though I do
Melissa:a lot.
Jam:Yep. Even though I do it, even though I love coffee, I do that a lot. And then you come back and it tastes very different. A lot of things have continued to react, continue to change, and those are the things that we taste Yep. When we take a sip.
Melissa:Yes.
Jam:And am I missing any of the big things? I didn't go into the, like, Shape of the molecule stuff you're talking about.
Melissa:Yeah. That's okay.
Jam:Yeah.
Melissa:Do you wanna do a quick review of of how radical reactions work, those 3 steps? I think that's good to talk about too because that part really explains why this reaction keeps going even while it's sort of on your shelf or why it's sitting out.
Jam:Right. So The radical reaction is starting with there being a a Radical is bouncing around as, an electron on its own.
Melissa:The first step is how the radical gets formed. Do you remember that? Nope. Initiation.
Jam:Dang it.
Melissa:So initiation, that's okay. You don't have to remember everything.
Jam:I remember termination.
Melissa:This yep. This is an authentic learning process.
Jam:I remember the last one. I remember the one I heard the most recently.
Melissa:You get you've gotten a lot of things thrown at you today. So initiation is it will It's literally the bond breaking apart. So you have a good bond that's, like, you know, 2 electrons being shared, and that heat or light Can initiate depending on what molecule you have. They'll break it up in a they call it a homogeneous break, so each side gets 1 radical.
Jam:Transubstantiation. Right? No. Is septu.
Melissa:Is that a religious word?
Jam:No. I think it's chemistry. Is The this step that you'd call going and taking one from another one?
Melissa:Yep. Do you remember what it's called? It's a plant word.
Jam:Propagation?
Melissa:Yep. So it just keeps making more of itself.
Jam:Yes.
Melissa:And so if you have several that initiated and several that are reacting, that might seem like, oh, well, you still only have 1 radical Mhmm. Because, You know, there's just 1 radical, whatever. But each molecule that was a radical will be changed. You know? Like, if I start out as One whole Melissa, and I get cut in half.
Melissa:And I'm only half of Melissa, so I still half of jam. Then now I'm a half Melissa, half jam.
Jam:Right. Right.
Melissa:And then you'll go steal half of whoever you can find, and then you're half jam, half the other person. And so every molecule Along the chain is changed. Every molecule that becomes a radical and is not a radical anymore has been transformed. Form.
Jam:It keeps being the musical chairs effect. There keeps being a person without a chair, and then you keep the person without a chair keeps going and looking. They find a different you have musical chairs. Mhmm. They steal a chair.
Jam:And then someone in that, the kid doesn't have 1, and they're moving on. Yeah. Keeps it never Resolves unless it does. Unless something can terminate it. Right?
Melissa:Mhmm.
Jam:And can can actually take that extra Like, John bouncing around, pair it with with another one
Melissa:Mhmm.
Jam:That isn't also taking it away from another one.
Melissa:Yes. Yeah. If the if 2 radicals find each other.
Jam:Right. Right.
Melissa:But even that molecule has been changed.
Jam:Right.
Melissa:So it's kind of chaos because every single molecule that has a radical comes out changed. It's not like you escape unscathed because you got another electron. That electron is attached to something. Right.
Jam:Right.
Melissa:So it's like Bringing stuff along with it. Bringing oh, maybe a good a good idea is, like, divorce. Divorce is the initiation step.
Jam:Uh-huh.
Melissa:And so now you have 2 single people that are you know, it's not really the They they've been severed from something, their family or whatever. And so now if one of those people gets remarried, Then now those kids, you know, from each marriage come together, and you've got a new family. Right. And then if that couple then gets divorced, You know? I I don't know.
Melissa:Yeah. Then the next group, the all the kids are coming together again. So it's like you don't You're not just interacting with
Jam:Right.
Melissa:Just the electrons. You're bringing the molecule that's attached to those the radical 2.
Jam:The history It matters. Mhmm. It it affects what happens next. Yeah. It's not just like a we're not talking about just a free electron with no baggage and no history and no whatever.
Melissa:The splitting a person in half was the best one. Right. Because it's, like, half most of half jam.
Jam:Yeah. But there's still some molecules there. There's just one Yeah. Yeah. Yeah.
Jam:Okay.
Melissa:Yeah. Yep. So that I think that step that radical reaction is important because the idea that the radical reaction will keep going indefinitely until the unlikely event of it finding another radical, which there's way less radicals than normal intact molecules.
Jam:Right.
Melissa:That's why it keeps going even though things are cooling down. You know? Yeah. They can just keep going and going. Not like, that Type of reaction doesn't have a natural endpoint
Jam:Got it.
Melissa:Except for the termination, which is less likely.
Jam:Right. But I
Melissa:think that's important to the idea too.
Jam:Got it.
Melissa:And a good chemistry lesson that that type of reaction exists.
Jam:Yeah.
Melissa:A little chemistry lesson for you.
Jam:And there's almost nothing we can do about it.
Melissa:Well, you can keep your coffee cold, maybe.
Jam:I thought in the, like, teen reaction aspect, even the, like, Trying to get to radicals to find each other. It's like there's so many like you were saying, there's so many things to react with. It's like Mhmm. Could you get all of these radicals to find other radicals and stop it? Nope.
Jam:The chaos will continue.
Melissa:I think what they do is, like, in labs, they really control the number of initiators that are present. You know, like, They really try to control the conditions for the reaction so that there is an endpoint. Right.
Jam:Right.
Melissa:But And you can have different molecules that form radicals that are more or less selective, but that's, you know, that's for your OChem to class, not for this podcast. Okay. Great. Well, that was really fun. I had a great time researching this episode.
Jam:Yeah. I think it's interesting. And you had to look at so much stuff.
Melissa:I did. I looked at so much stuff. I learned a lot. I didn't know about the taste buds thing, So that was fun. It was it was a good challenge.
Melissa:I enjoyed it, and I enjoyed being able to bring y'all along with me. So that being said, have you been enjoying anything this week, Jim?
Jam:I have been enjoying anything.
Melissa:Or lately, I guess, you know, in general. Yeah. Have to just be this week.
Jam:Yeah. I I have been. Thanks for asking. Be sad if I hadn't been enjoying anything at
Melissa:all. Yeah. That would be a little upset. You're, like, I'm not happy with my family. Yeah.
Jam:Yeah. I you mentioned this in our q and r, but I have been waiting to, like, sort of officially be able to use this in one of our episodes about the fun thing we share at the end of the week or at the end of the episode, until it was fully actually operational. But have been working on getting solar panels on my house for a while now. Mhmm. This, like, whole process actually started back in May.
Jam:And Finally, they have been installed, and everything's been checked out. And they have been given the okay to We operated, and the power company has connected them to the all all this that has happened. So many things people had to check and double check and different stakeholders that needed to, like, approve stuff.
Melissa:Mhmm.
Jam:And now we are producing solar power.
Melissa:Yay. You're producing are you giving it back to the grid if there's overages?
Jam:Correct. Yeah.
Melissa:Wow.
Jam:Most days during the day, we'll be producing more than we could use up in the morning. So we were pushing into the grid.
Melissa:Does the power company pay you for the for the electricity you generate?
Jam:Yes. They do. And Wow. It varies from place to place. City Denton, very solar friendly.
Jam:They pay you, they pay me, the same amount that I have to pay to use Power For Thin. Oh. So it's all equal. So I for the most part, it's basically the way it works. So, like, at nighttime, I have to use the power from the grid.
Jam:Mhmm. I didn't do the batteries thing. That's a long story. But I do that. We don't need to really hear for the most part.
Jam:So I'm using power from the grid. Mhmm. In the day, I'm producing more energy than I could really use, so I'm selling it to the grid. But, basically, I actually produce more, but the way it nets out in the it shakes out in the end of things, I'm actually most of the time producing more than I need, and so I actually don't have to pay Wow. The city for energy because I'm giving them I'm
Melissa:selling more to them than I'm buying. So do you get a check at the end of the month?
Jam:Now that, I don't know. I don't think so. In fact, I'd my thought is maybe it'll just be credits that stay there.
Melissa:Oh, yes. Like, in the summer
Jam:or something like that. When I'm using up when I'm using more.
Melissa:More at night. Yeah. So is that mean that it's better for you to do things during the day?
Jam:That's a good question. I think and the way people think about it is more just, like, across a year Yeah. Pathing. Because seasons are extreme. They change Yeah.
Jam:And stuff. But there might be some strategy there. I'm not sure.
Melissa:Well, that's amazing. Props to you, Jim. Way to be environmentally loving.
Jam:Yeah. It's pretty fun and cool. I'm actually a nerd, so I like to look at the numbers of, like, how much we produced and looking at
Melissa:Yeah. He texted us the 1st time they were generating power and
Jam:of, like, how much we've generated. So it's funny because it was, like, 0 zero zero zero zero zero one four. You know?
Melissa:I was, like, wow. That's amazing. And then that was kind of that was it. Very cool.
Jam:So that's mine. Mhmm. How are you? What's been good to you?
Melissa:Well, you already heard about this. So This is more for the listeners. So I I'm pretty open about the fact that I struggle with ADHD. But something I don't talk about as much as I also have anxiety and depression that I deal with as well Mhmm. Especially since my mom died.
Melissa:And Exercise is a really good way to treat all of those. Yeah.
Jam:But ice skating got to
Melissa:be too expensive and, You know, inflation. And it's a long drive down to where ice skating happens, and we just got a lot of other responsibilities now that I can't make that happen.
Jam:Right.
Melissa:So I knew I needed something to exercise and to to help treat my mind
Jam:Mhmm. Mhmm.
Melissa:And, like, My mental and emotional and physical, spiritual health, all of that. So I took the plunge and started a kick Boxing class.
Jam:Nice.
Melissa:So I have a membership there. I can do unlimited classes a month, and it's much more affordable than ice skating lessons Would be which you know, I love ice skating, so I'm sad about that. But Yeah. It's close by. It's like a 5 minute drive from my house, and I can do it every morning to get started with my day.
Jam:Nice.
Melissa:And so I'm really excited about my kickboxing lessons, and I'm hoping it will kind of help me Get out of a little rut I've been in lately with my brain and my, mental health. So
Jam:Yeah.
Melissa:So that's really exciting. Stay tuned for more information about that. I'm really I've heard that they do Club night, where when it gets dark outside because it's, like, windows in the front of the gym, it's dark outside on on weeknights now, and they'll do, like, Like, club music with, like, flashing lights type thing or, like, LEDs or whatever. And I'm like, okay. That sounds really cute and fun, like a party instead of just a workout.
Jam:Yeah.
Melissa:And my 1st class was really fun. It went by really quickly, and I like learning a new skill and being around other people Yeah. When I work out. So I'm really excited about that, and I just wanted to tell y'all. So yay.
Jam:That's awesome, dude. Good for you. 1, it's just fun returning things. 2, just trying something to see if it'll help. You know?
Jam:Like, a lot of evidence to suggest that it would. But
Melissa:Definitely. Sometimes we need
Jam:to shake stuff up. It's like, yeah, physical activity It's a huge benefit to our physical bodies and our mental health, but also, you know, may need to try something different. Yeah. It's like, maybe I've done this for a long time, And I'm having a hard time making that work in my schedule. Why not change it up?
Melissa:Try something new. And Yeah. I used to even being on campus, you have to walk into campus to work, and you have to Yeah.
Jam:You know, there's a there was a
Melissa:lot of, like, physical activity built into my day. Yeah. But when I switched to remote work, I don't have to go on campus very much Now I mean, I can, but I don't have to. Yeah. And so it's it's just it was hard for me to even leave the house.
Melissa:Mhmm. And this makes me get up and leave the house. And so I'm trying to sort of schedule my day. Like, I wake up, I go to kickboxing. I come home to the office instead of come home to home.
Melissa:You know, I get up, have my whole morning routine, And then I go into work.
Jam:Yeah.
Melissa:So I think that will help me have, a little bit more structure to my day. Yeah. And I think it will Be good for my mental health too, get in a routine, see people. So I'm really excited for that.
Jam:That's great. Very cool.
Melissa:Yeah. Well, thanks. Thanks for being excited for me, and thanks for being a coffee lover. I knew you'd be so excited about this episode and all of our listeners. And thanks to Alison for your idea to do this podcast because I had a great time.
Jam:And thank you for teaching us. Thanks for you know, you can always count on me. Be a coffee lover.
Melissa:Yeah. I bet.
Jam:Be interested in a coffee topic.
Melissa:I was so excited to tell you. I was like, I can't wait to tell DM about this.
Jam:Just plays right into my you know? It's like, I'm right in the demographic of this. It's like chemistry and coffee overlapping. I'm into I'm into it, and think a lot of our our listeners are as well. So if you have an idea like Allison did for a topic of chemistry in everyday life, please reach out to us at kem for your life .com.
Jam:That's kem, f o r, your life to share your thoughts and ideas. If that helps us keep our show going and contribute to cover the cost of making it, Go to patreon.com/chem for your life or tap the link in our show notes to join our super cool community of patrons. If you're not able to do that, you can help us by subscribing to your favorite podcast app or rating and writing our review at Apple Podcasts. That also helps us share chemistry with even more people.
Melissa:This episode of Chemistry For Your Life was created by Melissa Colini and Jam Robinson, and Jam Robinson is our producer. This episode was made possible by our financial supporters on Patreon. It means so much to us that you wanna help make chemistry accessible for even more people. Those supporters are Avishai B, Brie M, Brian k, Chris and Claire s, Chelsea b, Derek l, Emerson w, Hunter r, Jacob t, Christina g, Lynn s, Melissa p, Nicole c, Steven b, Shadow, Suzanne s, Sam n, Steven b, And Timothy p, thanks again for everything you do to make chemistry for your life happen.
Jam:We'd also like to give a special thanks to our team of reviewers who have checked this episode out before publishing. If you'd like to learn more about today's chemistry lesson, check out the references for this episode on our show notes or on our website.
